Hello! This is gwmax65 here. I am going to go in depth and detail on how I did my first Magnum Swap into my brother's 1965 Plymouth Valiant 200. The information I will be providing here is intended to help you guys out there thinking about, or are currently Magnum Swapping your early/later A Body Mopar. A lot of the information here is applicable to other Mopar bodies, and other car builds. Look into Magnumswap.com for more helpful info as well. If you would like to find something here quick, make sure to hold down Ctrl or Command + F to search specific keywords. If you are using a tablet or smart phone, use the 'find in page' option in Chrome. Make sure to accept cookies to view the pictures in this article, you may have to refresh the page again if something doesn't load. If you are using 'Chrome' and they claim this site isn't 'https' safe, click 'advance and proceed'. I would highly advise that you should read over everything written in this article, before small block Magnum V8 swapping your ride.
I purchased a relatively clean all original white 1965 Plymouth Valiant 200 back in 2014. An interesting story goes along with how it was acquired.. I was at the checkout at a scrap yard back in January 2014, buying some cool '70's Dodge hub caps for a '73 slant six Valiant I once owned in high school. I just happened to have my head turned slightly towards the window out front, and watched a white ratty '65 Valiant for the first time go down the road on a car trailer! We chased the owners down, eventually worked out an amazing deal, and later towed it back on home. It had an LA 273/4.5L Small Block V8, with an old cable-shift style torqueflite 904 transmission. She initially ran and drove, but it had no brakes at the time. The brakes were eventually fixed, along with a few other things, and I drove the Valiant all around for several months during my senior year of high school.
I also have a blue 1965 Plymouth Barracuda that's been in the family for over 20 years now. It's painted Maaco blue from the 80's, and had a later 1974 slant six drivetrain that I swapped in, back in 2013. I test drove the barracuda once after getting it going again with the '74 replacement slant six engine, since the original/factory one to the car was seized. Right away after the first test drive, I decided it wasn't enough power for me.. So the next day I wasted no time and pulled the whole 273 V8 drivetrain from the white '65 Valiant. Threw it all in the '65 Barracuda 1 week before graduating high school, achieving my long goal for driving the Barracuda there before the end, and embarking upon a crazy new life shortly right after graduation!
The '65 Valiant sat and sat, and after a few enjoyful months of driving around the Barracuda I ultimately decided to go with a different direction with the barracuda's 273 drivetrain due to a problem.. Sadly, the LA 273 began to smoke/burn oil, more than likely due to not having lead in today's gas + non-hardened valve seats.. The valve stem umbrella seals were also more than likely rock hard as well. I had a decent 40 over rebuilt LA 360 V8 engine I pulled from a 1986 Dodge W150 truck + a 2WD 727 transmission that I had intended to throw in it. But unfortunately, the wind blew the tarp up exposing the 360 engine to the sprinklers, so that idea got scrapped.. After searching a bit on the local classifieds towards the tail end of summer 2014, I found my first 5.2L/318 Magnum. With intentions, hopes, and ambitions high, I removed the Valiant's original 273 drivetrain from the Barracuda. Next I separated the valiant's original 904 transmission (cable shift/push button type) to use again behind the magnum, then, converted the 318 magnum to a carbureted setup and swapped it right into the Valiant! That's all in a nutshell...
The Barracuda was later magnum swapped in 2020 with a low mileage 360/5.9L Magnum. I still currently own the blue '65 Barracuda (owned 20 years strong now!), a magnum swapped '71 Satellite, '73 magnum swapped Scamp, '73 magnum swapped Duster, '66 magnum swapped Barracuda, '83 Magnum swapped CMX Dodge Mirada, '71 Hemi swapped D100, and an '81 Z28. I eventually gave this ratty 1965 white Plymouth Valiant 200 to my brother for him to enjoy for a while, up till it got parked for a while.. We bought this car in 2014, kept it until late 2020, then sold it to a good friend of mine. In 2022, we started to drive our classics over to our local car meet every Saturday/Sunday night, and it was a blast to race side by side with the Mopar I once owned! Still, blowing away the tires and going faster than any of my rides at the time, there was something special about this first Magnum Swapped Mopar.
In early 2024, the Valiant's life suddenly came to an end in a tragedy related to the 'single pot master brake cylinder'. If your ride has one of these, please, do yourself and everyone a favor and upgrade to a dual master cylinder. Make sure your emergency brake is hooked up correctly. I cover more about what happened to the Valiant further down this article under the 'Brakes' section.
Magnums are usually found in 1994-2001 (some 2002-2003) Dodge Ram's, Dakotas, Vans, Jeeps, and Durangos, an easy pick from the junkyard or online ad. A couple ways to figure out which is a 318 Magnum or 360 Magnum is to look under the driver's cylinder head. Right on the side of the block you will see the casting numbers, it'll consist of random numbers - ######## - 318 or 360. Or, look for factory stickers under the hood. The harmonic balancer from a 360 typically will have 3 open large slots/look larger, and uses a jaw-style puller to remove the balancer. While the 318 will look more solid, and uses a steering wheel type harmonic balancer puller. One of the best ideal ways to check to see if a Magnum 318/360 from the wrecking yard is most likely good or not, is to attempt to move the crank pulley by hand, or using a 1 - 1/4" socket on the crank bolt to turn it over. Make sure it'll turn over completely several times just in case, it's also easier to move the crankshaft over with the spark plugs out, beware of crud in spark plug tubes though. Also, do a quick inspection externally of the block itself, make sure there's no holes in the block & rods showing through of course, or cracks that are quite obvious (doesn't happen often).. Make sure there's not an excessive amount of rust in the coolant system as well, and mixed oil/antifreeze. You're mainly looking for a freely rotating engine, but this does not guarantee that the rod/main bearings, etc, are in good shape.
Another great thing to do is to buy an inspection camera for your phone off eBay. You can inspect the inside of the cylinder walls to see how everything looks. If you see cross hatches on the cylinder walls, it'll indicate a very healthy motor, if you see very glazed cylinder walls or lots of scoring, that could mean a few different things - 1. It could've over heated in the past - 2. Lots of miles/possibly not maintained well, etc. Inspect the tops of the pistons if you can, and check for pre-detonation (Usually looks like the surface of the moon, ok, maybe not that bad..) From my experience with these Magnums, it seems as if they don't care if they have very high mileage, such as 200,000+ miles. Typically they won't start smoking out the exhaust till around the 300,000 mile mark. Ultimately, it depends on whoever took care of it during the life of the vehicle it was in. What gives a major advantage with using these engines is originally having a tall overdrive gear behind the engine for all it's life, plus being fuel injected, and better sealing ring technology. Less rotations/lower rpms equals less wear, compared to the older days with your typical 3-speed 904/727 auto transmission (plus some 3-spd manuals). The magnums will have better cooling jackets, roller lifter valve trains, better flowing heads, better oiling systems, etc.
Now, some tech about automatic transmissions. If you are swapping from a slant six car, your 904 transmission will NOT work with any V8 as the bell housing & starter location is designed different (if manual, switch the bell housing). You have to get a specific small block V8 904 or 727 small block transmission, the 727 is beefier & can handle 600+hp stock no problem, it's also a bigger transmission both physically and internally. Be cautious when searching for a small block 727, as most of them out there are for big blocks. The 727 bell housings have very subtle differences, do a google image search to see the differences. Also, to tell the difference between a 727 & 904 right off the bat is to look at the oil pan shape, as well as the collar on the 904 at the bell housing. A lot of the guts in a slant six 904 compared to the V8 904 are interchangeable. Keep in mind however, the slant six 904 will have 3 friction discs instead of 4 in the clutch packs. Magnum & LA V8's have the same bell housing mount pattern.
An A-999/A-998 transmission is an A-904, but just a beefier version with an added extra clutch & steel plate in the high gear clutch pack direct drum. Approaching the 80's your A-999/A-998 torqueflites came equipped with low gear sets, mainly to combat with the lower horse power engines back in the day from the 80's, as well as heavier cars. The low gear sets in these transmissions can make a huge difference in your 1st & 2nd gear ratios if your rear gearing is between 2.45 - 3.23's, and you're putting out under 350hp. The A-999 will be a lock-up transmission, meaning the torque converter will have a large clutch inside to physically connect the input shaft directly to the crankshaft of your engine to lower the rpms, because a standard non-lockup torque converter will always be slipping. The A-998 will be the non-lockup transmission, just like a standard A-904, but more heavy duty (again). For those with higher HP builds, A-904 with 4 standard friction plates in both direct & forward clutch drums is plenty sufficient. You don't need to compensate with adding an additional friction in the direct drum to make it 5 'forward' "thin" frictions in the direct drum, just use a good shift kit with high line pressure, such as TransGo's TF-1/TF-2 shift kits, and your torqueflite will be golden.
If you're looking at building a mild or stock setup V8, stick with the 904 as they can handle up to 400hp stock + can be built to handle even more power (as high as 900hp with the right parts from C.R.T Racing/A&A Transmission). Shorter gears inside from the 904 compared to the larger 727 = more power to the rear wheels & it's also a lighter transmission in weight. For those of you with slant six cars, sticking with a 904 transmission will enable you to use your stock drive shaft as it's usually the same length from /6 to small block V8. The 727's tail shaft is much longer & uses a bigger/different spline count slip yoke. To put it shortly as well, the 904 is a safer transmission compared to the 727. The 727 usually needs a bolt-in sprag, in case in the event the stock one fails, it'll help lessen the chance of the large direct 727 clutch drum from exploding. When the sprag fails, depending on how high the rpm of your motor is at the moment of failure, times that by about/around 2.5x is how fast the direct drum will end up spinning, at which point they can/will come apart. Billet direct clutch drums are also sold to save your feet/legs. Scatter shields won't always protect you, look up '727 explosion - barracuda' and you will understand why. There's not many instances recorded out there of 904 direct drums exploding because the rotational mass is much smaller in comparison to the 727, and Chrysler used some pretty big ol' rivets to hold the over-running clutch/sprag in the case.
The #1 failure in Chrysler automatic transmissions is either not having your kick down adjusted correctly/not hooked up (seen this too many times..), and too much HEAT. Make absolutely sure that your kickdown settings are as close to a true 1:1 ratio with the throttle, from idle to W.O.T. If using a kickdown cable, make any necessary modifications to your kickdown lever at the transmission if needed to achieve the correct geometry/funtion, it matters. An external transmission cooler mounted in front of the radiator is ideal & highly recommended for the longevity of your transmissions life. Hooking it up to the radiator like the factory does is still fine, if the transmissions not seeing a lot of crazy high power & torque constantly. But beware, if the radiator's internal trans cooler ever fails, you can have antifreeze & ATF mix together.
Something that needs to closely be pointed out.. Say if you were doing this swap in a B/C/E - body, those cars are much heavier than the A body platform.. So take into consideration how much harder a 904 transmission has to work to move those cars, more heat generated will usually be a resulting factor. Many B-bodies still came with 904s from the factory (unsure if C-bodies ever did), but a vast majority were also small/big block 727s on the B/C/E bodies. Once more, it's always a good idea to invest in an external trans cooler, as well as a good shift kit for your valve body so your shifts are crisper. Shift kits also help the transmission stay cooler with less slippage between shifts, this saves a lot of life on clutch/band material over time.
Now back to the Valiant's Magnum Swap. -- Please bear with me about the format with all the back & forth in this article, it's still going under much revision, just like a project! 11/15/2024. -- Also, please make everything you do look neater than what you see in some of these pictures below, what you're seeing is early stuff when I was learning years ago..
When I first got the 5.2L/318 Magnum for the '65 Valiant, I decided to do away with the stock fuel injection and go carbureted for simplistic reasons, less wires! The first thing I did was document/take pictures all around of the motor, then began to clean it up.
Before I got too crazy disassembling stuff, I had to figure out what I needed. First thing I ordered was a re-gasket/re-seal kit. Thermostat - 195° Fahrenheit (Gates 33509) -- 180°F is better if you aren't using fuel injection. Since I decided to go with a carbureted setup, the intake manifold would have to be changed. I bought an Edelbrock 7577 AirGap intake manifold off Summit Racing (When it was cheaper...). The Edelbrock 7577 intake manifold has the intake bolts going vertically instead of at an angle like on the LA motors, so it's the perfect fit on any stock magnum engine. However, much, much more affordable airgap intakes are now manufactured from various companies/sellers on eBay, they work on LA + Magnum V8s and still flow great! For a carb (fuel make it happener), a friend of mine sold me an Edelbrock 1406 (600cfm) 4BBL carburetor. The edelbrocks work really well, and are simpiler to work on compared to most carburetors out there. I had to source a special bracket made by edelbrock to bolt onto the carburetor throttle lever, so I could still use my stock kick down linkage & throttle cable. This part is the Edelbrock 1481 bracket, and it can be bought from the autoparts store, ebay, amazon, or summit racing. I had to pull the nut & kickdown piece off the previous 2bbl carburetor from the 273 V8, to bolt onto the new edelbrock 1481 bracket for the kick down rod to snap onto.
Most people will buy a Lokar kick down cable kit to do away with the hassle of adjusting/modifying stock kick down linkage. There is a detailed subject that I cover about how I installed my Lokar throttle cable and kick down cable further down this article.
For an ignition system I decided to go with an HEI All-In-One Distributor. Using this type of distributor required new female end spark plug wires to work. So I went onto MSD's website, searched for the small block Magnum 5.2L/5.9L spark plug wires and bought those. The part number for the MSD Street Fire spark plug wires I bought is - #5532. You can still use the stock magnum spark plug wires as well, but my original magnum wires were toast. The LA V8 distributors have female type spark plug sockets, and male posts on the magnums, just like the HEI distributor. For spark plugs I went with E3 spark plugs, the part number for these spark plugs are - E3.48. The advantage of having the HEI all-in-one distributor is you get a much hotter spark, + no more ballast resistor - just a 12V ignition wire tied into the existing ballast resistor harness wires, and the ignition coil sits inside on top of the distributor. Plus there's a simple tachometer terminal/connection right next to the ignition connector.
Update 2/19/2017 - The HEI distributor decided to start failing after nearly 2 years of using it in my 2nd Barracuda, am switching to the MSD 6A ignition box with a new stock distributor + MSD Blaster 2 Coil, don't expect to have anymore problems after that. I am assuming it began to fail because it wasn't seeing a consistent 12V upon startup from the existing old ballast wires, this could've been fixed with a 12V relay. ---- 3-13-2022, from another source in regards to cheap HEI distributor units, they claim the advance timing springs/weights may be faulty and partially activated at idle, along with another issue involving the bushing on the shaft. Essentially leaving 30-40hp on the table, while a set of new springs could help resolve the issue. Don't cheap out on ignition systems, buy them from a reputable company such as Summit Racing.
Update 7/24/2018 - I am still experiencing ignition issues in my 2nd '65 barracuda, even with the fairly new MSD setup, swapped to a 6AL box, no difference, swapped to an old stock electronic distributor, no difference, changed alternator, voltage regulator, still no difference, acting like its sometimes firing off all cylinders and then 6-7, will be unhooking the main firewall harness to see how dirty/corroded the contacts are, could be responsible for pulsating voltage between 13v-14v & ignition troubles. ---- 3/13/2022, pulsing voltage problem has been partially isolated to the voltage regulator ground, pulsed less when a negative wire was ran from the negative battery terminal over straight to the body of the voltage regulator (upgraded to the '70s adjustable VR), but what really seemed to help was wiring a 4-pin relay that would bridge direct 12V power to the VR, over to the positive side of the battery, acting like a voltage sense wire for the voltage regulator, 'in a sense'..
(Above pic is of my 2nd '65 Barracuda when it still had a 273, clear cap and rotor bought separate off eBay)
I thought about going with headers but found out TTI headers cost a fortune on early A bodies, but there's a more vast header selection for the later A bodies because in '67 they widened the shock towers for more space + ease of throwing big blocks in, so I stuck with stock LA exhaust manifolds. You can run Magnum exhaust manifolds, it's a little bit of work for fitment, but it can be done, and they flow so, so much better. On the driver's head of the motor towards the rear, some material needs to be ground off so the exhaust manifold will seat flush to the head.
Since I decided to keep the stock serpentine belt set-up, I found out that I needed an AC delete bracket pulley which they sell on eBay or Summit Racing --
Dorman Air Conditioner Bypass Brackets 34178 (RNB-34178)
When I got the AC delete bracket, I noticed rather right away that it wouldn't bolt up to my accessories bracket because the hole mount spacing's are different between a 'Ram van' motor and a 'truck', so I headed on over to the local pic-a-part junkyard to pull an accessories bracket from a '94-'01 Ram truck to make the AC delete bracket bolt up. Note how I had to cut out a 2"x 2" square on the accessories bracket for the heater hose fitting to fit/work on the intake.
Update 7/24/2018 - My buddy pointed out my serpentine belt wasn't long enough and that it wasn't wrapped around the idler pulley, which of course caused slipping later on (didn't quite realize that at the time), corrected that issue with the AC delete bracket. You don't need an AC delete bracket if you can get the correct sized serpentine belt for manual steering cars & route it correctly. You don't need it for power steering cars either if you can figure out the correct sized belt, and, route it correctly. In fact, you really don't need it at all, I'm just here to inform you how to install it, just, bolt it on, or don't.
I ordered a later style ('70s) new voltage regulator & special 2 wire bulk head connector in order to use the magnum alternator, very easy to wire that up. Don't buy a cheap Chinese voltage regulator, specifically look up 'Mopar voltage regulator', it'll be black with white/yellow text, shaped like a rectangle and have a triangular connection with 2 little posts, they're made in the USA and will charge correctly/last sooo much longer. They will lessen the risk of over charging your battery then having it explode, yes, that can happen.. When you install the voltage regulator, make sure you have a PERFECT ground surface, so take the time to get some of the black wrapping off one of the bolt holes on the VR. I just ran a ground wire from the negative post of the battery right over to the bare metal potion on the VR. When sourcing the special VR plug connector, search 'Mopar voltage regulator connector' on the interwebs.
It doesn't matter which color side of wire you choose, green or blue, for example we'll go with blue. The blue wire ties into the ignition system (Best to hook up at ballast resistor harness wires since it's the main ignition source), then take some extra wire, hook it up to one, of the 2 FLD posts on the alternator. Then hook the other end of the wire to your ignition harness as well. For the green wire, take a long wire, hook it up to your last/unused FLD post on the back of the alternator, and splice the other end in with the green wire on the Voltage Regulator. Get about a 12 gauge thick wire (or thicker) about 2 feet long, hook it to the BATT. (Charging terminal) post on the alternator, then hook the other end up straight to the battery's +/Positive post.
4/30/2017 Update: The Mopar VR has been charging between 13.4-14V in my 2nd Magnum Swapped '65 Barracuda with no problems.
I DON'T recommend using your existing factory alternator BATT./charge wire because the magnum alternators typically put out higher amps compared to an LA - V belt driven style alternator. You could risk causing an electrical fire because there's an ammeter/ampmeter on the back of the instrument cluster panel that can only take so many amps. The factory ammeter/ampmeter was never a great section of Chrysler's wiring in the majority of their cars, and were often the culprit of burning, many, cars to the ground. Those 2 thicker gauge wires back there commonly get hot enough with a higher amp alternator, to start melting, then ground out. So going straight to the battery in this case between the alternator & + post, bypasses that ammeter so your electrical system is much safer. You will need to either go under the dash, or partially remove your instrument cluster panel to tie both the thicker gauge red & black wires together (both are positive wires). They are hooked up to your ammeter/ampmeter (the gauge that says D - C), just snip the ends, and join the two. Source an aftermarket 12V gauge to monitor your voltage.
Since Magnums don't have a mechanical fuel pump eccentric or hole in the magnum timing cover for mounting a fuel pump, I went with a low psi Holley fuel pump from summit racing. There's a variety of the low psi electric fuel pumps out there, the most common is the dead-head style, meaning there is no return port back to the gas tank. A lot of these type of low psi electric fuel pumps usually have a self-fuel pressure regulator built in.
I discovered having a magnum out of a ram van has an advantage for making the magnum power steering pump work better in any A-body, because the pump sits significantly lower compared to the dodge trucks version. This made it so I didn't have to relocate the battery to the trunk. I went to the 'house of evco/house of hose' to have custom power steering hoses made in order to work with the magnum power steering pump, over to the factory power steering box.
MAGNUM POWER STEERING HOSES - 2/2/2018 -- I found out that there's this little factory adapter that is usually screwed into the power steering box for a female end PS hose to screw onto. As I was looking at the PS box on a 1973 Plymouth Duster, I noticed there wasn't one there. (Working on my 4th Magnum Swap with a 360 in that car). So quite literally all I did was remove the PS high pressure hose (both male ends) from the LA 318 PS pump, hooked it up to the Magnum PS pump, and everything WORKS!! So I can't quite 100% verify that if you get a 1973 high pressure power steering hose, it will be the one you need, because the LA 318 I pulled came from a 1984 Dodge Truck, so that hose could very well be from a 1984 PS high pressure hose. Your low pressure PS hose should hook right up no problem as well as it's just standard 3/8" line. Make sure you use specific power steering hose and not fuel line, because the power steering hose material will be able to handle the high temperatures that move through the power steering system.
While I was helping my buddy work on his 1971 Plymouth RoadRunner with a 318 Magnum Swap, we found out that the power steering hose he bought specifically for a 1971 Plymouth RoadRunner wouldn't fit into the power steering box. Along with the 7/16" to 1/2" factory adapter removed, because that end of the hose required a 1/2" male end to screw onto, not 7/16". So he found a 1/2" to 1/2" adapter that screws right into the pump like the other adapter, got it ordered from O'reillys site, and it all should work out. The other end of the high pressure hose still screws into the Magnum PS pump with no issues.
10/18/2019 - PS STEERING HIGH PRESSURE HOSE
So on my 6th Magnum Swap in a 1974 Plymouth Duster, here's what's going on with the Magnum power steering high pressure hose situation. On another '71 RoadRunner, I used a new 1973 A body high pressure PS hose, and it would never seal right at the magnum PS pump. I couldn't ever figure it out till I finally looked closer and saw differences between both tube flares on the Magnum style & LA/old style high pressure lines, that bolt into the back of the PS pump. Wish I took some pics to show here, but there's a normal flare on the 73 PS hose that would seat perfect in it's factory LA pump, but, the Magnum requires a different flare style.. I would call it a ring flare because the tube is straight at the end for maybe 1/4", then there's a ring in the metal that's barely thick. It goes straight right after that to the rubber portion of the hose. What's weird is, I bought yet another new '73 A-body LA style high pressure PS hose for the '74 Duster's 318 Magnum Swap (with a magnum pump), installed it, and somehow it's not leaking. So maybe it's by chance the wrong flare/LA style flare can find a happy spot to seal in the magnum PS pump. The same hose configuration, again, in the '71 RR with a magnum PS pump, would simply not seal. So, if you get a '73 A body/Duster high pressure hose, it may or may not work for you. You could, also have one correctly made at a local specialty shop that deals with high pressure hoses/fittings.
I bought Mopar Magnum valve covers off eBay (back when things were more affordable..). Had to buy an oil filter angle adapter + special bolt that has oil passages & comes with gasket + washers, from eBay. For an oil pan since all magnums have the truck style oil pan, I went to summit and bought a sum-g3536 oil pan, essentially it's an LA 360 car style mid sump oil pan. LA 273/318 oil pans will NOT work on any Magnum motor (I have about 2" of oil pan clearance to center link with this new Summit oil pan). Typically, on LA oil pans there's factory dents in the pan for the center link to clear when maxed out on the turning radius. The oil pan mentioned above won't have any issues, the center link will naturally put a small dent/recess in the new pan over time with driving, so you'll have a good center link turning clearance. I also had to order a new mid-sump oil pickup tube (See MEL-72-S2 on Summit Racing).
If you are magnum swapping into a slant six car, early or later A body, you will need a V8 center link for oil pan clearance. If, for whatever reason you still find yourself with the lack of oil pan clearance, you can attempt to shim your motor mounts up with thick washers. Slant six people, you can try this and maybe get by using your stock center link without swapping to a V8 center link, but, this is only applicable to pre '72 cars since in 1973 they went to the spool type motor mounts.
For later A bodies, you DON'T have to change your K frame out if your car is a slant six, simply go to Schumacher Creative Services website for V8 conversion motor mounts. Early A bodies share the same K frame between a slant six and small block V8 - Schumacher also makes motor mounts for Big Block swaps in early and later A bodies, heck, they even make slant six conversion mounts if you want to go backwards in performance! They have just about everything you'd need. Trans-dapt also sells more affordable motor mount conversion kits that can work decent in '67-'72 slant six A-bodies.
I re-used my stock LA motor mounts from the previous LA 273. The casting of the passenger motor mount ear on a magnum V8 is flipped around, compared to the LA 273/318. You can however, still make it all work with a long high grade 8 bolt -- Read my thread below about this.. That being said, something important to take note is between an LA 273/318 and an LA 360, the motor mount perches/ears are different in dimensions, usually the LA 360's is more narrow. On the Magnum 318/360's however, they are the same, only on the passenger side, those dimensions are also based off the LA 273/318. It's only the passenger side that is flipped around/mirrored on the Magnums in comparison to the LA's. It would also be ideal to make or get a torque strap that ties the block, to your K-member, so it puts less stress on the motor mounts overtime.
Small block 318/360 Magnum Swap - Motor mount answers for those with questions
I bought a Champion 3 core aluminum radiator, and failed to take notice of which side the water pump faces, so I had to combine 2 radiator hoses and an exhaust pipe to couple them together along with hose clamps, it still works just fine, just looks a little goofy. For a cooling fan setup I decided to go with an electric fan, mounted in the front. Also bought a $10 chrome car-style oil dipstick tube. The magnum water pump I bought is the GATES 43034.
I proceeded to clean the surface where the intake manifold meets the heads really good with a straight edge blade. Make sure you have clean lint free rags or plastic bags in the intake valley to catch junk. Have a shop vacuum on one hand as you get the excess junk removed with the other hand. They say to not use the front and rear 'china wall' seals that come in your gasket kit for your intake manifold, because it can still cause leaks. Use some high temp RTV (gasket maker) and run a nice 1/4" bead across those surfaces + in the corners, and smear some around your 4 square head water jackets. Then move forward with installing your new intake manifold gaskets. There are NO intake dowel alignment pins on magnums. I like to take 2x spare long bolts with the same thread pitch as your intake manifold bolts, then cut the heads off and use them as an alignment tool. Once the new intake is in place, take a mallet and tap around the intake to help seat it in place, make sure your gaskets aren't moving around a bunch. There's a bolt down sequence you're supposed to follow, look it up on google images. Be very careful when you torque the old intake manifold bolts, they can snap really easily. I'd say just go snug and a bit more if you don't use a torque wrench (this is what I did after reusing the old bolts). After other instances of breaking the old magnum intake bolts after re-use, and having to go through the hassle of removing the intake just to clean everything up again, I will always use new grade 8 bolts from the hardware store. Shim them up with extra washers if needed, and torque them to spec. With new intake bolts, go through the torque sequence multiple times as the bolts will 'work themselves in' each round.
Next, I drained all the oil out of the oil pan, and let the RTV/gasket maker setup for at least an hour on the intake manifold before I flipped the engine upside down. Once flipped, I pulled the pan off, and cleaned the deck surface up really good. Should've pulled the rear main cap off to replace the rear main seal at the time but didn't... Make sure you do. If you do, make sure you off-center your rear main seal halves slightly by at least 1/8" as this provides a near perfect seal. Pay very close attention to how the lip of the rear main seal is supposed to face, and use the plastic looking installation tool provided in the kit, so the sharp machined surfaces of the block doesn't gack up the seal during installation. When putting the main cap back on, be sure to oil up the bearing a little. Put the cap back onto the block, carefully work it back & forth till it seats flush. Snug up the main cap bolts, insert the front crank bolt, tap it with a hammer, and do the same on the back of the crank as this helps re-seat the bearing. Then torque the rear main cap bolts to spec and move on to the next step!
The new oil pan from summit racing arrived, and I found out that you can still use the magnum (leak proof) one piece oil pan seal! If it looks like the rear piece of the seal won't seat on the pan, it will, it'll stretch itself around the pan when bolted down. Sometimes when you get these new oil pans, the flat surfaces might be slightly bent, but, they will flatten out when bolting the pan down to the block. I will usually put a little bit of RTV/gasket maker in the corners of the oil pan before putting the seal on, as well as the corners of the timing cover + rear main cap corners. Watch closely that the oil pan seal stays where it's supposed to when installing the pan, because sometimes the front large lip of the seal likes to suck itself in. The truck magnum oil pickup tube was swapped out for a car-style mid-sump. It's shorter in length, and closer to the crank for the new/any LA 360 car style oil pan to work.
Threw the new one piece seal on the pan, put the pan on, bolted it down & torqued it to spec (or just pretty snug..). Once again, if you find your new oil pan's sides are slightly bent from factory, they will usually straighten themselves out as you bolt it down to the block, no problem. Double check that your drain pan bolt is snug!!
I flipped the motor back up again, then replaced the valve covers & gaskets, and forgot at the time to do some grinding work on the driver's cylinder head, so that the LA exhaust manifold can sit flush. We'll cover this next..
The above pic was from removing the Valiant's 318 Magnum again later on. The old front pump seal of the transmission lasted a few months before it completely failed and was puking excessive amounts of fluid. While everything was out, I went back to grinding some material off of the driver's cylinder head so that the exhaust manifold would seat flush and not leak. See the bare metal showing on the driver's cylinder head? That's where you have to grind some material off. Now back to the initial magnum swap.
Before I bolted up the early style 904 cable-shift transmission, I still wanted to use the stock magnum flex plate, however, the LA 273 flex plate would've bolted up no problem.. 1-2 of the holes on the magnum flex plate that mount onto the torque converter needed to be slightly drilled more open in order to get everything to bolt up correctly. At the time I failed to realize that the PILOT of the torque converter was smaller than the pilot hole in the back of the crankshaft. The pilot is back nub of the torque converter that recesses into the back of the crank shaft. I still managed to bolt the early 904 torque converter up, unfortunately, slightly out from truly being centered up. This was most likely due to having the slightly 1-2 flex plate TC mount holes opened up more/not keeping the TC 100% centered up. I probably should've just used the LA stlye flex plate at the time. The pilot is responsible for centering the torque converter up on the crankshaft.
This article is focused on automatics, as I do not have experience with manual transmission setups. As the transmission is already bolted to the engine, and you are at the point of bolting up an 'early' 904 torque converter.. Use a crow bar to gently pry the TC upwards and center it up in place. Install 1 bolt at a time, and only go snug. If more than 1 hole won't line up, this means that you are off on the rotational bolt pattern. Spin the torque converter to the next hole till you can get all 4 to bolt in. Then, use some spray paint to mark one of the TC bolts to flex plate & torque converter so if you need to remove everything in the future, bolting the TC back up to the flex plate will be much easier (you could do all of this before bolting the trans to the engine and save some hassle). Sometime between '67 and '68 they changed the crank shaft pilot hole size to a bigger circumference.
To this day, the torque converter appears to still be slightly out of round while rotating. This could mainly be because of the pilot of the torque converter being smaller. Not lining things up properly when bolted to the magnum flex plate that has 1-2 holes slightly drilled more open as well. Or, this may also be an illusion because of the spray paint used to mark 1 torque converter bolt.
Side note, fast forward nearly 10 years later (2024), I tore apart this early 904 transmission and found hardly any bushing wear in the front pump, and the snout of the torque converter looked untouched, which is good!
Some important things to note -
LA 273 & LA / Magnum 318's are internally balanced, meaning, there are no counter weights added to the flex plate or harmonic balancer.
However, the LA 360/ Magnum 360 is externally balanced.
A lot of LA 360's usually have a large weight welded to the torque converter for external balancing purposes, while the 360 Magnum usually has weights welded to the flex plate. According to Magnumswap.com, you CAN NOT use an LA 360 harmonic balancer or LA 360 flex plate with weights on a Magnum 360 (same applies if the torque converter has a large weight welded to it), because, they're balanced different externally from each other. On the 318 Magnum/LA motor there are no counter weights on the flex plate or harmonic balancer because they are internally balanced. However, that doesn't mean that any torque converter won't have some smaller extra counter weights added to them, in fact, most TC's will usually have smaller weights added to balance the torque converter itself.
If you are running a 360 Magnum, sometimes, you can remove the harmonic balancer pulley to swap over to a V-belt style, often times, both the harmonic balancer & serpentine belt crank pulley are attached to each other permanently. In that case, it may be worth making a trip to the wrecking yard to find one that are separable, or, go to summit racing for a specific 360 Magnum harmonic balancer (if you are planning on using V-belt accessories) if not, continue to use the serpentine belt 360 harmonic balancer for the serpentine driven accessories. Another thing to mention, it's recommended to use a little bit of blue thread locker/loc-tite on the flex plate bolts and torque converter bolts.
Again, pre '67/'68 TC's/Crank shaft pilots will have a smaller circumference. Don't forget, LA 360's and Magnum 360's are balanced differently externally, from each other. You can NOT throw an LA 360 flex plate/harmonic balancer on a 360 Magnum, otherwise it will cause excessive vibration. You can however, make the stock existing magnum flex plate work! Which is something I'd highly recommend re-using on the 360 Magnum, since there are already external weights in place. If for some reason you don't have a flex plate, go on summit racing's site to order the correct flex plate for the 360 Magnum, or make a trip to the bone yard. The flex plate from summit is usually moon shaped, so the cutout on those flex plates are what makes the external balancing work. LA 360's are externally balanced in two different ways on the rear section. The flex plate, or, a large weight welded to the torque converter. If, you are swapping from an LA 360 to a Magnum 360, make sure you knock the large weight off of your torque converter if you have one to re-use the torque converter.
The one thing that just about killed me on this swap was not replacing the FRONT PUMP SEAL before swapping everything in the first time.. It is the main seal that goes into the front pump, around the input shaft (usually has an orange/red color to it). If you have the chance while the transmission is out, do not hesitate to replace the seal(s), or rebuild it! They're easy.
Remember to seat the torque converter in the transmission's front pump correctly. Do not slide the transmission onto the torque converter with the converter bolted to the motor.. While you are installing the torque converter, will drop further into the front pump at least 3 times to be completely seated. It can help using something to bolt to the lower bell housing and push against the torque converter to help it stay in place and not slide out while moving the transmission about.
Next, I bolted just about everything essential up to the magnum, but the serpentine belt system, and then took it off the engine stand. The transmission was re-mounted afterwards.
I bought an engine lift plate that bolts onto the intake's square bore, where the carburetor would be. I've found using a set of carburetor studs that will only be used to lift engines works the best. Some of the thicker removable washers that go over exhaust manifold bolts work great over the carburetor lift plate studs. Next I used my wonderful (crap) 1 ton engine lift, and had an awesome friend around with me to help out. We pulled the hood off the Valiant, moved the motor with transmission attached into position, and moved the car towards the drivetrain while I began to lower it. What I've found over the years during the process of installing drivetrains is, if you use the closest hole on the engine lift plate towards you, it will angle the drivetrain nicely downward during installation. Then, you can swap over to the middle or rear hole as needed after you find a good resting spot to sit the drivetrain down, while, using a floor jack on the tail shaft of the transmission.
Note, there's a firewall lip that the ball n trunion (1965 & down automatics) adapter/tail shaft has to jump across. At the time, my buddy eventually had to hop on in and stand on the transmission as it went in to achieve the angle needed for installation. Once cleared, swoop, right on in it goes. Make sure to have good weight added to the back of the engine lift if the legs don't extend out far. Usually 2x 12V batteries does the trick, or a person on the back, if they don't jump off of the lift to help... You CAN make this all happen without removing the hood, it is a tight squeeze, but doable! Sometimes it's easier to install the drivetrain with the car high up in the air on jack stands. For those with the later 904/727 (1966 & up automatics), try to not gack your tail shaft seal boot when installing the drivetrain. You can zip tie a rag over the seal to protect it from the sharp edges of the firewall lip, and keep it away from any crud in the area that may want to enter the tail shaft during installation. Quick tip, wrap a rope or something at the end of the tail shaft to get the angularity needed as you pull the car towards you during installation, while pulling a rope at the same time.
I noticed things weren't looking right with the motor mounts, then found out they were backwards/on the wrong sides (common mistake).. Swapped sides and right on in it went. I loosely secured the motor mounts with the thick motor mount washers & nuts, to allow for wiggle room when bolting the transmission cross member in place. At this point while the drivetrain is slanted downward, it is the most ideal point for installing your transmission cooler lines, kickdown cable, etc.
When using a Lokar kickdown cable, I like to leave the 1 tail shaft bolt a little loose so that if it comes in contact with the floor of the car, it has some room to move. Don't forget to snug that bolt back up later.. Then, use a floor jack on the tail shaft (or pan with a 2x4) of the transmission to lift it up more level. I will usually have the early biscuit style transmission mount already bolted into the cross member, then, slide everything into place to bolt the transmission mount/cross member to the tail shaft. With the later spool type mount, it's best to have the mount bolted to the tail shaft, and then slide the cross member in place. Leave the two tail shaft to transmission mount bolts a little loose for further adjustments when installing the cross member, then snug everything up when ready.
Those with kickdown cables:
Pay close attention to how your kickdown cable operates, remember, you need about a 1:1 ratio between the kickdown & throttle (from idle to WOT). On the early A body cars, sometimes your kickdown lever comes in contact with the floor. You can make clearance by recessing the floor further in, or try slightly bending the kickdown lever, or trying using another lever. I like the kickdown levers that point closer to the bell housing. If you have enough length on your kickdown lever, you can, drill additional holes as needed to achieve the proper kickdown to throttle ratio.
This is a critical part to the longevity of your torqueflite's life span.
Those who are going to use the factory kickdown linkage:
The way to adjust your kick down linkage correctly is, lengthen your kick down cable/rod, open your throttle just barely until you start to feel the kick down pressing the throttle pressure rod on the valve body, and you should be set. Once more, you basically want a 1:1 ratio with the throttle and kick down, so when you're just barely pushing on the throttle, the kick down lever should already be pressing the throttle pressure rod on the valve body (go to the point of when you start feeling resistance). You may have another adjustable rod to play around with right by the firewall. There is some normal room of kickdown adjustability for making the shifts occur sooner, or later. Having your kick down/throttle pressure set right is VERY IMPORTANT to the longevity of your transmission's life.
Some people out there will think it's ok to disable the kick down/leave unhooked. However, doing this WILL burn your transmission up, because the clutch packs/kickdown band inside won't be pressed firmer together for minimal slippage as you're driving, especially while getting on the throttle. Manual/Reverse manual valve bodies will NOT have a kick down setup, because they are full-time line pressure.
Once everything was all said and done, she was a SLEEPER.
This build was done for around $1000, every penny spent was well worth it. They're very fun and torquey motors with lots of life left in them! It's hard to kill a Magnum V8. Keep on reading for more important information with Magnum Swapping your ride!
1965 Plymouth Barracuda - 318 MAGNUM V8
Also, back in late 2015 I traded my 1974 Plymouth /6 Duster for a 1966 Plymouth Barracuda 273 Commando - thread on that car is here...
1966 Plymouth Barracuda - Commando 273 V8
Fall of 2016. -- I just recently got done with my 2nd magnum swap on my 2nd '65 Barracuda. I had to get my 904 push button/cable shift type transmission rebuilt because I had lost reverse but still had all gears in drive, that was kinda my justification for doing the swap since the trans had to come out anyways. The barracuda had a healthy roller 273 from 1967. I got the 904 rebuilt, hooked it up to my 2nd 318 magnum, swapped it back in, and what do ya know, it doesn't have reverse or even 1st gear! I had my transmission guy put a shift kit in it but some reprogrammer rod from the kit wouldn't fit, so 'most' of a shift kit was installed. Turns out, the cable shift 904's/727's have quite a few differences compared to the 1966-up units.
I tried a couple different things with the valve body, pulling it out, adjusting the line pressure, adjusting the kickdown band, putting the VB back in (several times), it got old fast. I eventually pulled that old cable-shift transmission back out for the last time, and decided to use a later 904 that came from a 1974 Plymouth Roadrunner. My transmission guy is currently swapping the new guts he threw in the old 904, into the newer 904. pre '66 904's are very problematic. It mostly sucks having to constantly keep an eye on the shift cable adjustments, plus, the ball n trunion driveshaft was a bad setup from the get-go.
Update 2/5/2017 -- Got the 2nd Magnum swap build finished, hauls A!!. I ended up getting a B&M ratchet star-shifter to install in the Barracuda so it would work with the later 904 transmission. Already had a slip yoke driveshaft made to work in it. Will further update my thread about this Barracuda pretty soon.. With this magnum swap I decided to go with the V belt style for that nice classic old-school look, and it's working pretty good so far! I used an LA 360 timing cover, bought a fuel pump block off plate, kept the LA 273 water pump so I could bolt the LA alternator up with ease, plus have this water pump for the future use my 273 LA power steering setup, if we ever convert from manual. I used the LA - X shaped flex plate. The newer ('66-up) 904 torque converter pilot will fit like it's supposed to in the back of the crank shaft, because it's 1969-up. O'Reilly's has the correct 10" LA-273/318 (non-weighted/internally balanced) X shaped flex plate that'll bolt up no problem on a 318 Magnum - Part # FRA303.
Hope this info helps, post/message with questions, think I've covered it all in this article. Keep on reading for more below! Also, check out my other threads & YouTube Channel full of Mopar -
gwmax11
Mopar or No Car!
Keep on reading - More important Magnum Swap info!
Intake fitting holes/intake bolt down sequence:
Here is a picture of the intake manifold bolt torque sequence. One side is 12 8 3 1 5 9, the other side, 11 7 4 2 6 10. The heater hose adapter size on the front right of the intake is 3/8", next to that on the left is 5/16-18" -- This is where I installed the temperature probe for my electric fan. You can also plug it with an NPT plug - assortment kits are found at the auto parts store. Then on the very left is where the temperature probe goes (1/8"). On the passenger side towards the rear of the intake manifold runner there is a 3/8" threaded hole, just like the heater fitting hole, except, no water goes through here (just air). Plug that with an NPT plug as well if you don't plan on running a brake booster. The bypass to water pump hole size on the intake is 3/4", the large brass fitting comes with intake Edelbrock manifold. If you need one of these large fititngs, usually you have to buy them separate from Edelbrock.. For the heater hose fitting and thermostat housing, I pulled them from the stock magnum fuel injection intake manifold. I cleaned them up with a wire brush wheel on an angle grinder, and painted the parts with VHT high-temp silver paint.
Starter:
For a good starter, I bought a $60 rebuilt mini (high torque) starter off eBay. They crank 2-3 times faster compared to the stock dinosaur-dolphin starter, and use less power when cranking. They are also perfect for the, 'oh crap my engine stalled!' situations. The mini starters give you a lot more room for header tube clearance as well. On my automatic transmission, I left the inspection plate off. Most people will, because they get bent so easily, and then your left with this annoying noise caused by the torque converter bolts rubbing against the plate.
Picture of a 1970's internal dual field Voltage Regulator - Note, this is not a Mopar voltage regulator, this was before I discovered non Mopar voltage regulators had BIG issues, buy one made in the USA!
Breather's and PCV
For a valve cover breather I sourced an Edelbrock brand from the local auto parts store, and it came with it's own grommet to install with ease. For the other side, I used an old PCV valve and snugged it into a grommet. Usually, when you buy Mopar Magnum valve covers they will come with a bag containing 4 different valve cover breather/PCV grommets to use. On my 2nd Magnum swap in the Barracuda, I bought a different style PCV breather that's as big as the Edelbrock breather, which has a snout to slide to still connect a hose. The other end of the hose connects to the front of the carburetor. Grommet sizes needed are about 1 - 1/4"
Throttle cable bracket
For a bracket to hold my throttle cable in place I used my existing throttle bracket from the 2bbl LA 273 V8. The intake bolt size on the Magnums are 5/16" - 18 thread pitch. I went to Lowe's and got a 6" LONG bolt, 2 nut-washers, then pulled 1 intake bolt out on the drivers side in relation to where the throttle cable is, secured the throttle cable bracket on the bolt along with the nut washer, then threaded in the long bolt to a point, then secured the bolt with the 2nd nut washer on the intake manifold.
Update: Get a higher grade & much longer bolt that moves this bracket up higher, so that the throttle cable doesn't put too much downward stress on the throttle shaft of the carburetor. This here currently could cause the shaft to wear excessively over time & create a permanent vacuum leak.
Some bolt measurements
The bolt size to hold any small block mopar on an engine stand is 3/8"-16 (16's the thread pitch) for the top 5 (only 2 will be used, the first 2 away from the top center bolt hole) and recommended 2x 7/16" bolts & nuts (any thread pitch, just make sure the nuts have the same thread pitch for 2 bolts that pass through the lowest 2 holes on the engine), also get a few washers. I highly recommend getting grade 8 bolts as they are very strong. On my setup where my 360 Magnum is currently stationed on an engine stand, the upper 2x 3/8"-16 bolts that thread into the block are 4 - 1/2" long with 20 washers each bolt to take up slack in my combination (40 washers total between the upper 2), the thickness of the washers are 0.055" according to my digital calipers, 16-18 of these washers = about 1". The 2 bottom bolts are 8 - 1/2" long, using 2x 7/16" washers and 2x 7/16" nuts. You can come up with your own combination if you like.. I could've used shorter bolts and less washers but it works as it is for now. A rotatable engine stand from Summit Racing dramatically helps this entire process, you simply spin around a crank handle to change the angle of the engine without needing any help flipping the engine over like on a standard cheap engine stand.
IN CASE you need an extension for your kick down rod, you can buy 2 feet of 1/4"-28 all thread rod from the hardware store/online -- It is the same size of the kick down adjusting rod. A new 2ft threaded rod can be cut to your desired length. For a coupler, you specifically have to type in on ebay/amazon '1/4-28 coupler nut'. Bought some off eBay for around $11. Your existing kick down linkage from an LA V8 WILL bolt up no problem on a Magnum head. Don't forget (for early A body people) you can add more throttle pressure/length to your stock kick down system by also adjusting the vertical middle rod behind the motor. I attempted to use some kick down linkage off a later A body ('74 Duster to be specific) in my '66 Barracuda, and it would NOT work because, the pivot that slides over this little rod, that screws in the side of the bell hosing of the trans, would run right into the stock exhaust system. So I abandoned that setup, then pulled the stock kick down linkage to that car ('66) from my 2nd '65 Barracuda, then threw it back on, and all is well. Again, most people will get a LOKAR kick down cable to do away with factory linkage. This is the route that I went with in my 2nd Magnum swapped '65 Barracuda, along with the Lokar throttle cable. It is pretty easy to hook up and adjust. 'WhoSaidTyler' on YouTube made an excellent video explaining on how to install a Lokar kick down and throttle cable setup. Below you'll find a section explaining how I set mine up.
LOKAR KICK DOWN & THROTTLE CABLE - INSTALLATION
Alrighty, so first off I went on eBay and ordered these 3 individual Lokar items for my 2nd Magnum Swap in my '65 Barracuda - Lokar kick down cable (Lokar KD-2904HT) - Lokar Stainless Steel Carburetor Bracket and Stainless Springs (Lokar SRK-4000) - Lokar Universal 24" Stainless Steel Throttle Cable (TC-1000HT) if you can find a 1ft version that would work just perfect too. These things are getting pricey............
LOKAR CABLE BRACKET INSTALLATION
I got the Lokar carburetor throttle/kick down bracket mounted to the driver's rear carb stud, this can be a little tricky installing. Next I pulled the carb stud out, positioned the bracket in place, then slid the carb stud back through, and loosely bolted it on snug since there's some more adjustments to make. On the Lokar carb bracket, take note of how there's a little threaded stud and nut on the bracket itself right next to the carb, all this does is orients the bracket. You can hook up your return spring setup either way, old school in the front, or how Lokar instructs to install their setup which works great, either way. I wouldn't recommend having both setups because it causes the Lokar carb/throttle/kick down bracket to bend in a strange way, thus causing your cables to become lose over time, I'd recommend doing it the Lokar way. If you're having an issue with your idle being too high and are compensating with too many return springs, double check for vacuum leaks, as well as your throttle cable tension setting.
LOKAR KICK-DOWN CABLE INSTALLATION
Before going any further, when you find yourself at the point of needing to cut/shorten a throttle/kickdown cable, make absolutely sure whatever piece that is supposed to be attached to the cable is already on the cable. The strands can potentially fray out after a cut, and make it nearly impossible to get the piece back onto the cable. There is a trick that sometimes works by taking a small zip tie, and going around the cable strands with the zip tie as it realigns the them once more. DON'T CUT THE THROTTLE AND/OR KICK-DOWN CABLE TOO SHORT.
Once everything was finally out of the pointless excessive shrink wrap, I looked over the instructions carefully. I threw the barracuda on jack stands, then unhooked all of the stock kick down linkage. Next, I used the little hex angle allen wrench provided to undo one of the ends of the cable in order to slide the cable out of its protective sheath. After that I moved forward with mounting the cable sheath to the tailshaft section of the transmission.
Remember as the instructions say, DON'T remove the 'clamped' ends of the sheath, just leave those on there.. Unless you need to slide them up the sheath to trim the sheath down for your application. It's a P.I.T.A to get them back on if you do remove those pieces. So, have the sheath adjuster nuts backed all the way off to the point where you can have just a few threads showing. Doing this will give you more movement of the cable during operation. The kick down cable sheath will have a mount that mounts to the Lokar throttle/kickdown cable bracket. Bolt the mount of the kickdown cable to the backside of the throttle/kickdown bracket. Line up both upper holes for when you install the Lokar throttle cable sheath later. Don't tighten anything up, just go finger snug at this point. Then for the other end of the kickdown sheath, you'll see on the sheath that there's another mount with a bend in it. This mount will be bolted on one of the transmission's tail shaft bolts. When you're looking at the tail shaft bolts, the bolt you will need to remove is the left/drivers side bolt that's 1 up from the 2 lower tail shaft bolts, it's a very tight space on early A-bodies, and sometimes (not always) you may have to pull the transmission cross member out with a floor jack supporting the pan to lower it for access.. I'd recommend test fitting the mounting bracket/cable sheath once mounted, so again, don't tighten the bolt till you've decided if you need to either slightly bend the mount a different way to just barely move it away from the rear transmission cooler line nut, or take a hammer to slightly dent a recess in your trans tunnel a tiny bit for just a little more room to work with (early A body problems yay..).
Once you have it mounted to the tail shaft, have at least 2-3 threads showing on the adjuster sheath nuts there, then tighten them up a bit. Next, slide your cable back in from either the top, or the bottom. The bottom half is better left alone in the first place so you don't have to bother with sliding so many things back on as compared to the carburetor end. When you have the important stuff slid back on the kickdown cable, plus already have the cable installed back in the sheath, start working on the transmission end once again. You will need to remove your kick down lever from the shift shaft of the transmission to bolt up the tiny ball hitch/pivot looking nut. You'll want the ball end facing upwards, but, it can be installed upside down depending on whether it will clear your shifter linkage/cable.
When I remove these levers I'll undo the bolt which secures them to the valve body, then slide a flat blade in between the shifter lever, and wiggle each end till it works it's way up & off. When reinstalling the kickdown lever, you may need to slide the flat blade in between the halves of the lever to open it up a little more for ease of re-installation, because if you tighten the securing bolt too hard, it clamps it tighter.. It will close itself back up on the throttle pressure section of the valve body once the bolt has been snugged back up. Make sure it is snug and that the lever does not loosely wiggle at all, if it does, that may cause a shift quality issue. You may have to slightly bend this lever to barely clear your stock/aftermarket shift rods/cables. In a lot of cases, you may need to get a different kick down lever, as there's a LOT of different kick down levers out there for different applications.
Something I've found when using these Lokar kickdown cables, is that it's better to have a kick down lever that points closer to the bell housing. Because of the the geometric angle at which the cable must pull at, while the cable is already mounted at the tail shaft. This is a critical section to pay attention to so your transmission has as a true 1:1 ratio between your throttle at idle to Wide Open Throttle. You can drill additional holes in the lever if needed to obtain the correct 1:1 window of the ratio, and mount the little ball hitch/pivot piece accordingly. Improper kickdown settings can result in shift quality issues, as well as the longevity/life of your torqueflite 904/727 transmission.
So, once you have that all ironed out, it would be really simple to snap the kick down cable on the shift shaft lever's ball hitch/pivot. Then, reinstall the lever back on the shift shaft section of the valve body. For the adjusting threads of the Lokar kick down cable (at the transmission end still), I went just about all the way out/most slack, but still have up to 3-4 threads of the adapter screwed on. Most of your adjusting for this cable will happen up at the carburetor. Before you pull the car off the jack stands, check everything over again. Make sure your cable isn't rubbing against the trans cooler line nut, check that nothings binding up weird, and that the geometry of the cable looks good (check this when the kickdown is fully hooked up to the carburetor). My recommendation is to hook up a small return spring to the bell housing ear, then over to the kickdown lever so just incase the spring is weak in the valve body, it will fully return the lever to it's resting 0-out spot. Doing this will help mitigate strange scenarios where you are decelerating and feel it shift back into 2nd for a split second while coming to a slow stop. Once you've verified everything's hooked up correctly at the carb end, get the vehicle off jack stands/ramps and move onto the next thing.
Now, for finishing up at the carburetor. Once your Lokar cable is slid back into the sheath, and secure nut, install the other flat looking ball hitch/pivot at the lowest hole of your carburetor's throttle lever, while having the flat ball facing towards you. Then slide/click the Lokar mount piece of the cable onto it. You should have lots of slack at this point. So, here's where you can decide if you want to go with front or rear return springs for the throttle cable, again, I'd recommend the rear Lokar setup since it works great. For installing the Lokar return springs, you'll want your tear drop piece mounted to the back side of the kick down flat ball hitch piece (on the other side of the carburetor throttle lever). Once that's installed, get your return springs and hook them up to the lowest hole of the Lokar throttle/kick down cable bracket. Secure the kickdown carb nut when you find the position you like. Check later if you need to flip your return springs around if they interfere with the high idle cam or anything else that might be in the way.
When you've dialed all that in, move your adjuster set-nut around on the Lokar kick down cable, so that it almost has tension on the kick down lever when you're barely opening the throttle. Too much throttle pressure/kick down tension of the cable can delay the shift, too little will make it shift too soft/not shift or not 'kick down' correctly when you need it to. With the larger nuts securing both sheaths of the throttle & kickdown cables, I like it set where there's the least amount of threads showing (on your left side of the bracket), so that the cables can work more freely during operation.
LOKAR THROTTLE CABLE INSTALLATION
Story time -- Later on, my 2nd magnum swapped 318 began to not quite run right when I was still using the factory throttle cable setup.. It acted like it had a vacuum leak of some sorts. Someone informed me with how I had my stock throttle cable positioned at an angle, which can put excessive stress on the throttle shaft itself. In turn, it will wear out the bushings of the carburetor body, and cause a permanent vacuum leak. So I found it reasonable enough to get a LOKAR throttle cable to go along with the Lokar kick-down cable setup. Not only for this reason, but for smoothness of pushing down the gas pedal. I could have just got a longer high bolt to let the stock throttle cable mount sit higher, but then it would most likely run right into the Lokar throttle/kick down bracket.. So, once my Lokar throttle cable arrived I went and studied how everything works with the old stock throttle cable setup.
The factory throttle cable sheath from inside is secured with an interesting looking C-clip that's usually a fight to pop off. I used a thin flat blade screw driver to persuade it off. The bottom black plug that helps keep the cable attached to the throttle pedal bracket, was removed to remove the throttle cable. Out everything came.
I found that the securing nuts of the throttle cable sheath itself were too small compared to the hole opening of the stock throttle support firewall plate, therefore, I had some thinking to do. I removed the firewall throttle pedal assembly plate, then found a washer the perfect size. I welded it on with my cheap harbor freight 120V flux welder, and it was exactly what I needed to get the job done. Note: After thinking about this later on.. you don't have to go to this extent with a welder.. Using larger washers and securing the nuts of the Lokar throttle cable sheath is enough to get the job done right.
On the Lokar throttle cable, just like the kick down cable, remove the lokar cable from the sheath, starting at what would be the carburetor end. Then, install the sheath on the throttle pedal firewall support plate over a couple different sized washers, you will also need a washer on the other side as well. If you find too many threads are showing on the inside-end, add more washers on the firewall side. Hook the other end of the sheath up to your Lokar throttle/kick down bracket at carb end (only if it's the right length). If you need to shorten the sheath, a thin grinder disc on an angle grinder works great. Just make sure you scoot the solid piece at the end of the sheath further up so it can be slid back into place after the cut. Then, reinstall your throttle cable starting at the gas pedal end. I'd recommend removing the weird looking end adapter of the throttle cable since it's kinda redundant to have that there if the stock gas pedal rod can hold the ball end of the cable in place no problem (like I did, works either way..), put the black securing plug back in, then hook up your ball hitch nut at the top hole of the carburetor's throttle lever right next to the big hole where/if you'd have front throttle return springs.
You'll more than likely notice how much excessive Lokar throttle cable you have, so you'll need to cut it down with dikes. What I do is, pop the kickdown cable off of the carburetor for a bit. Then, for your Lokar throttle cable setup, take the pivot piece & adjuster off the throttle cable, adjust the adjuster so that it is almost at full length, but have it screwed in at least 5-6 threads. Then, pull your throttle cable all the way out till you hear/fell that the gas pedal is all the way up inside. As you are pulling the cable, move the cable towards your pivot ball hitch that is attached to the throttle of the carburetor (make sure the choke/high idle cam is not set at this point/the throttle blades are closed for normal idle). As you match the center of the ball to the cable up, mark the cable 1-2" longer with a sharpie. Next, take the pieces you slid off the cable and slide them back on. But, make sure to have the part that attaches to the carburetor now removed, so that the cable can slide on through the pieces. Double check your cable length once more with it pulled out to be sure you have everything marked where you need it. Cut the cable at the mark you made. Then, screw the adjuster piece (that pop's onto the pivot) back onto the cable, and start adjusting the cable length & adjuster threads to where you have just a little bit of tension at idle on the cable. Secure the cable's adjuster hex nut very good with the allen wrench provided in the kit. Have someone check that you are at Wide Open Throttle with the pedal to the floor (or just about) by having them try to push the throttle open as you are depressing the gas pedal. Make any adjustments as necessary. No adjustments should happen at the cable sheaths that attach to the Lokar throttle/kickdown bracket, unless you find that you need to allow the cable to move-about more freely. Now, you should have enough cable length and adjustability at the threads of the adjuster to get you back on the road!
Older style throttle return bracket
For a throttle return bracket on this first magnum swap, I went and bought an aftermarket piece from the auto parts store and got my throttle return springs installed there. It is bolted on the drivers side front runner of the intake manifold. Use this method if you aren't using Lokar cables.
Carburetor Spacers
I wanted to use a 1" carburetor spacer on the AirGap intake to perhaps get a little more low end torque, but it makes the carb sit way too high, and would need a hood scoop.. So I am running without a spacer, got about a 1" gap from the air cleaner to hood as is.
Update, a 1/2" phenolic resin carb base spacer with a 1/2" air cleaner spacer works great with a drop-base air cleaner in an early A-body.
Oil Filter Adapter BOLT Pictures
Priming The Oil Pump
This probably should've been one of the first things to mention... It's a good idea to prime your oil pump/engine. In order to do this, you must first buy a OIL PUMP PRIMING SHAFT (Part # for the shaft -- P4286800). You'll also want a drill to attach the priming shaft to, have it set to go clockwise. Now before you pull the distributor, take note on where the rotor is pointing at, because when you remove the drive shaft gear that the distributor flat blade shaft rides on inside, you'll only have 6 ways to get that gear drive shaft pointing the rotor in the correct direction 'hex shaft'. You will want the rotor to be pointing at the same spot as it was before when the drive shaft gear is put back in. Ok, so remove the distributor, get some fish line, wrap it around the drive shaft gear down inside, as you are pulling you might need to get a flat blade screw driver on the drive shaft gear, rotate it clockwise to let it raise a bit, to help it come out. Once you've pulled the drive shaft gear out, you'll notice how the shaft from the drive shaft gear has 6 sides, this will play a great role, again, in where your rotor is supposed to point correctly.. Insert the drill with the oil priming shaft down on the oil pump, make sure you got clean 10-30W oil in the pan, and then begin running the drill clockwise for about a minute. It is ideal to have someone help move the crank over as you're priming the oil pump so you're not just sending oil up to 1 head, but rather both Remember, doing this will throw your position off of where your rotor should be pointing once the drive shaft gear has been reinstalled due to the fact that the rotating assembly will be in a different position before you started. A solution to this, make sure you're at TDC on cylinder #1 (Driver's front head) with both intake and exhaust valve closed (on the compression stroke), then you'll be able to dial in the drive shaft gear to rotor position correctly, usually with #1 pointing towards the center of the carburetor. Once done priming the oil pump, put the drive shaft gear back in, slide the distributor back in and if you notice that the rotor isn't pointing where it was, you'll have to pull the distributor back out, insert a flat blade, rotate clockwise 1 out of the 6 faces over of the drive shaft gear, put the distributor back in, repeat the process if needed and you'll get it where the rotor was pointing before, if, you chose to not move the crank shaft at all while priming the motor. Or ignore all of this and make and find out where your new position for #1 sits and go from there.
Priming The Oil Pump Part 2.
DON'T use an impact gun when you're priming the oil pump, that's guaranteed to break something, it has to be a drill, and has to be spinning fast enough to actually see oil flowing with the valve covers off. The idea is to get oil flowing through everything important in the motor, bearings, etc. vs spraying the cylinder walls with lubricant and calling it 'good enough'.
The reason why you really should have the drive shaft gear that the distributor rides on back in the factory correct position is because when you undo all your spark plug wires in the future, or perhaps a next owner does, they're gonna go off the relative position of where each spark plug wire goes according to any Mopar ignition timing picture/diagram, so if that gear is off how ever many sides out of 6, you can be spending a lot of time moving spark plug wires over trying to figure out at what point it's gonna run, rather than just simply looking at an ignition timing picture and getting right on the first time.
Remember again, there's only 6 ways the drive shaft gear will go back in because the shaft is hex shaped. Once you got the drive shaft gear back in, make sure it's where it needs to be like the factory had it, you can turn 1/6 faces over as many times as you want with the gear STILL INSTALLED, just rotate it clockwise with a flat blade screw driver.
Exhaust port difference LA vs MAGNUM
There's a slight difference in the center 2 exhaust ports on Magnums in comparison to the LA's. They're spaced out farther compared to the LA heads and this could pose a performance problem if you use LA headers/manifolds, as well as sealing. The performance on my first Magnum swap in the Valiant is however going really well with stock LA 273 exhaust manifolds. Don't forget to grind the drivers side head for header/manifold clearance, to make it sit flush. Some say you can actually make the Magnum exhaust manifolds work, I've tried this on my early A bodies only to find they run into the firewall, so unless the firewall is modified to recess an exhaust pipe, don't believe they will work on early A bodies, have seen them working on later A bodies, but a rare sight to see stock magnum manifolds in cars. Also, if you are going to use stock exhaust manifolds, you DON'T have to swap the thread studs from LA to Magnum, you can make the Magnum studs work perfectly fine with combining the exhaust bolts/nuts from the Magnum and the LA motor..
10/30/2024 -- Update: You actually can make magnum exhaust manifolds work in an early A body, but it's tight. On another '65 Barracuda I swapped the passenger side over to a magnum exhaust manifold, it is very close to the firewall. Thankfully I had a section of the exhaust still bolted to the magnum manifold from the truck it came out of, and I was able to angle it just right to weld it up to a section of the factory 273 single exhaust. I cut the center cross over of the original 273 single exhaust to make both banks a true-dual exhaust setup, and just welded a flat section of metal over on the driver's side where the exhaust used to come to a Y. It made a MASSIVE difference in performance!! Can only imagine how much more there is to gain by doing the driver's side too! There is another thread on here that talks about converting to magnum exhaust manifolds. For the driver's side, it's a little more tricky. You have to shim the driver's motor mount up with some thick large washers, then convert the manual steering pot coupler to a U-joint style coupler. You also have to cut the steering column back a few inches closer to the firewall as well. You may also have to grind a little bit of the casting away on the exhaust manifold. It will fit, but it will be extremely close to the steering rod. I will be doing the driver's side conversion soon and update how it all works out.
LA vs MAGNUM Timing Cover
Here's a picture of the Magnum timing cover on the left and an LA 360 timing cover on the right. I remember some stipulation on the front main crank seal when I was working on converting my 2nd 318 Magnum to a V belt style. Seemed like some LA 273, even LA 318 timing covers I got my hands on they would have a cast recessed in the timing cover for the seal to sit against, but on the LA 360 timing cover there's no recess, just is a push through seal, same exact seal as on the Magnum.
LA 360 timing cover from an 1986 motor, old seal out (blue) - Now on my 2nd 318 Magnum.
Picture of a timing cover I bought to replace the corroded timing cover on the LA 273 in my 2nd '65 Barracuda (Before the 2nd Magnum Swap), note how there's a cast lip on the front, the seal for this timing cover is smaller in circumference and is installed on the back side. The ignition timing spots are still on same drivers side. But, from what I know on '65 - 273 timing covers the ignition timing spot is on the passenger side, with a section that bolts to the timing cover + has the same action going on with the cast lip.
Broken Dipstick Tube? EZ OUT!
Another thing that typically happens is dipstick tubes can easily break on Magnum engines, the best way to get them out is to use an EZ out bit! Turning the bit counter clockwise grabs into the piece you are trying to remove. While using vice grips and a hammer as you are going counter clockwise, it'll eventually get a bite in the broken tube, keep going till you can't twist the bit anymore, but not so far that it causes the tube to expand and hold-up on removal. Once I got a bite on the broken tube with the EZ out, the oil pan was already off so I took a flat blade screw driver, then slid it down the cast tube part of the block till it touched the EZ out tip. I continued to smack the tip of the EZ out with a mallet & screw driver, out the broken tube came! When I bought a new chrome dipstick, I had to do some very slight grinding on the bottom end of the tube that goes into the block, so it would slide fairly easily in with some resistance into the block, along using a gob of high temp RTV/gasket maker to ensure it won't leak. You have to make sure you bottom out the tube against the tube ring to the block, to ensure that you are getting an accurate reading on your dipstick.
Using LA Exhaust Manifolds
If you choose to use LA exhaust manifolds like I did, you MUST get the heater cross over valve on the passenger exhaust manifold taken out, they typically stick in inconvenient positions and CAN cause burnt exhaust valves, very bad for performance.. Once you've got the heater cross over valve removed, you'll have 2 small holes that'll need to be plugged, simply just weld them up, and make sure you have a very clean surface when doing this. Take it to a machine shop if you don't have the equipment needed to remove the heater cross over valve. I used a sawzall with a fine metal cutting blade, and then trimmed the existing rod/ends down so they were flush inside the port. The ends shouldn't move if your cross over was hard to turn, but if they pop out, weld em in place as plugs. You can use Magnum exhaust manifold gaskets no problem, same for LA gaskets.
Stock Magnum Heads & Performance Heads
The majority of cast-iron Magnum cylinder heads are subject to cracking at the valve seats over time. Most magnums I've worked with have shown small cracks between the valves, this is common. Usually, the cracks aren't severe enough to cause a significant loss in power/compression, but some can. You cannot fully tell how far the cracks go back until you have the valves removed. These cracks can be repaired, but at an expense.. Usually, it's better to source new ones, which leads us to this next! Aftermarket manufactures engineer and produce so many different heads out there. One brand in particular that sticks out for the small block magnums are 'Engine Quest' heads. They are a better designed & flowing cylinder head with added material in areas needed to reduce any chance of cracking. These are specifically made to replace Magnum heads. There's an article out there either on the HotRod network or Mopar Muscle that talks about how to make an easy 400 HP out of a 5.9/360 Magnum with Engine Quest heads. They are sold with the 1.920 intake valve or 2.02 (1.620 exhaust). Check into hughes engines website for these cylinder heads. As far as I've researched, hughes is the only place that installs bronze valve guides in these heads to help prevent sticky valves (something you absolutely do not want to have happen..). You can order them in either intake bolt patterns - LA or Magnum.
Hughes Engines.
Hughes engines is a great place for Magnum performance parts, they KNOW their stuff! Don't let this head cracking portion change your mind about doing a Magnum swap, even if there are cracks, usually, they are minor/more or less hardly affect performance - based off of my experience.
Oil Filter #'s
I usually always buy Wix oil filters, for the shorty filter it's the 51085 - Use this if you aren't using an oil filter angle adapter. For the longer Wix filter which filters more oil (better), go with 51515. Use the longer filter anytime you can, but know that it may not fit depending on exhaust location.
Utilizing The Stock Fuel Injection
I don't have very much info on how to make the stock fuel injection work as all the swaps I've done have been carbureted. I would suggest searching on FABO for more info. There are also quite a few facebook groups about Magnum EFI swaps, and very knowledgeable people in them. I found some useful video/info content on YouTube, check out this guy's channel (MontanaLowGear), he goes through how to Magnum Swap into a Jeep TJ and using the stock fuel injection, very detailed & specific on how to wire everything up correctly!
MontanaLowGear
Removing A Drive Train As A Unit Via Engine Lift
1st - I'd start off getting a 2 ton engine lift, either borrow one or buy one, got a 2 ton lift off eBay. I'd also recommend getting one with extendable legs for better leverage, or at least have a friend stand on the back of the engine lift as the motor is coming out (car batteries work too).
2nd - If your intake manifold is a 4bbl, you can remove the carburetor, buy a lift plate for around $20 at the auto parts store, and bolt it on in place of the carburetor. Yes, those little carburetor studs can actually take the load of hundreds of pounds.. Make sure you have thick washers on before nuts, I used left over Magnum/LA exhaust manifold washers. If you have a 2bbl carb intake on your V8 instead, buy a chain to bolt to the motor going from corner to corner on the face of the cylinder heads. If a slant six, bolt the chain onto the front face of the head and on the top bolt hole that usually secures a vacuum amplifier in place. I bolt mine there to achieve the desired angle for pulling a slant six drivetrain out with the transmission attached. However, there are 2 factory lift bolt holes on top of the cylinder head next to the intake/exhaust manifold.
3rd - Once you have an engine lift setup + lift plate or chain acquired, proceed to drain the radiator by opening the petcock on the bottom of the radiator. Once drained, remove the top and lower radiator hose. Remove your transmission cooler lines from the radiator. Remove the radiator. Remove the throttle cable & kickdown setup if needed. Remove fuel lines going to the fuel pump. Remove any wires going to the alternator & temperature sensor + oil dummy light/pressure sensor. Unhook the battery. If you have power steering, remove the power steering hoses and pump from the motor. Remove the belt driven cooling fan from the water pump. Optional, remove the alternator. Unbolt exhaust pipe(s) from exhaust manifold(s), use PB blaster if you need to get rusty bolts to come off. Remove the shift rod or shift cables going to the transmission. Remove the connector for the safety neutral switch/reverse light switch. Remove the starter from the bell housing (You can let the starter just rest on the center link if you don't want to completely remove it). If your driveshaft is the normal slip yoke type ('66-up cars) make sure you have a oil drain pan ready to catch transmission fluid. I usually get by leaving the transmission cooler lines hooked up to the trans as I pull it out, sometimes it can get caught on the front core support and be a little problematic to get out. You can remove the trans cooler lines from the trans before pulling if you want to. Remove the 1 bell housing bolt on the transmission that holds the transmission dipstick tube in. Pull the dipstick tube. Sometimes, there's another small bolt holding the dipstick tube to the transmission right at where the tube goes into the trans, remove that to remove the tube.. Remove the oil filter angle adapter if you have one, and remove the oil filter. For V8 cars, remove the drivers side exhaust manifold from the cylinder head and let it hang there on the gear box as you pull the drivetrain out. The LA drivers exhaust manifold usually hugs around the steering gear box. Remove the transmission cross member. Undo motor mount securing bolts.
Lastly, get the lift plate or chain or engine leveler (for changing the angle of the drive train when coming out, easiest method) bolted on. You can remove your drivetrain without removing the hood, get creative.. Then, get the lift attached to the lift plate. I like to have the hoist's hook length slack shortened up as much as possible for the max lift. If using a chain, make the chain have as less slack as possible, then use a couple bolts at the hook so the chain won't slide, and then start lifting it up as you push the car backwards. You might hang up at the firewall lip to transmission tunnel, so have someone stand on the trans to get past the firewall lip, and to help achieve the angle needed for getting it past the front core support. Wrapping a tow strap around the tail shaft helps by pulling from under the K frame/center steering link to obtain a better angle. You can also always use an engine leveler instead as bolts in 4 corner intake bolts on a V8 or front and back faces of the heads, easier for changing angles with a simple crank handle. Swoop, right on out! The pic below is from pulling the 273 drive train out of my 2nd '65 Barracuda while using a chain, and friend as counter weight since my 2 ton didn't come with extendable legs, just vertical ones...
Setting an Edelbrock carburetor up
If you are using a 4BBL Edelbrock carburetor (carter/weber), this is a quick guideline for setting up your carburetor to run smoothly. These carburetors are also very easy to rebuild, in comparison with most holleys/other carburetors out there. Have your smartphone handy to take pictures. With the carburetor off of the engine, you should check your float levels as this is the #1 important thing towards calibrating your carburetor. Remove the 2-3 small cotter pins securing the rods to your accelerator pump, choke, and high idle. Remove the accelerator pump screw and remove the parts. Loosen the screws securing the top doors to the metering rods, rotate the doors so that the rods pop up, remove the rods + springs. Remove all top securing bolts and separate the top half from the bottom of the carburetor. To check your float level adjustments, take a small ruler or measuring tape and measure how far the floats drop. You want about 15/16" to 1" of a drop. To adjust the float drop, remove the pin that holds the float in place, remove the float, take some pliers and gently bend the small tab the direction needed to raise or lower the float drop setting. You will need to reinsert the float with the pin and check your measurement several times till it is correct. Once that is dialed in, move onto setting the float rise.
To set your float rise, now flip the top upside down so that the floats are not hanging. Grab a 7/16" drill bit, then slide it between the gasket and the float. To adjust the float rise, carefully bend at the point where the float is soldered to the adjuster tab, while making sure you do not bend the smaller tab. Once the drill bit barely touches the tip edge of the float, you are set. Double check the float drop once again in case you need to re-adjust it. To test that your needle & seats are working, try blowing air in the fuel inlet with the top still upside down. If you cannot hear or get air to blow by, the needles are seated properly and working. You may need to clean the needles a little with mineral spirits or with a little bit of carb/brake cleaner on a lint-free rag. Double check that there isn't any junk in the lower body of the carburetor, but while you are there, just blast everything out with some brake cleaner and an air hose.. Put everything back together.
I like to insert the metering rods & secure the doors before snugging all the bolts down to the top of the carburetor. Next up is adjusting your idle mixture screws. Turn both of your idle mixture screws all the way in, but do not go tight with them as this can cause damage to the body. Then, back both screws out about 2 full turns, while counting each half turn of the screw. This should be a good baseline for setting the mixture screws to where you can further fine tune them later with the engine running at operating temperature. Adjust your idle screw to where the throttle blades barely expose the transfer slots. Make any necessary adjustments to the high idle cam as needed. Make sure the port on the back of the carburetor is plugged with an NPT fitting/plug, unless you are using it for a brake booster. Up front, the left smaller port will be used for your vacuum advance timing. The right smaller port that sits lower is for ignition timing that goes off of the manifold, plug this port. The large center port will be used for a PCV valve, if you don't want to use a PCV (not recommended -- unless you have a breather or two..) it can be capped. Hook everything up, including the fuel line.. Fire the engine up, let it get to operating temperature, and make any adjustments needed to the idle mixture screws/high idle cam/idle.
You may need to further tune your carburetor with different sized jets & metering rods, only do this once you have your ignition timing dialed in. The colored spring that goes over the metering rods are more for cruising/part throttle driving. There are 5 total different rated springs, with orange being your baseline average spring. You can visibly watch the metering rods pull off the jets with the engine running. Just loosen the metering rod door screws, move them half way out to partially reveal the metering rods, tighten the screw and fire the engine up. With a few quick revs you should see the metering rods pop up for a split second. While experimenting with these springs, you will be able to tell if you need a lighter or stiffer spring.. Only make changes to your metering rod sizes first while tuning, before changing your primary jets. Keep notes on what combination you find that works best with your application.
Ignition Timing
Firing order between an LA and Magnum engine are the SAME. The distributor spins clockwise, and the firing order is 1 8 4 3 6 5 7 2. Make sure you have verified that the rotor of the distributor is pointing at cylinder #1, and that you know that cylinder #1 is at Top Dead Center with both intake/exhaust valves closed. It's ideal to have a tachometer hooked up at this point if you aren't experienced with knowing by ear with where your rpm's are roughly at. Have your distributor clamp snug, but loose enough that you can still rotate the distributor to make adjustments. Next, with the vacuum advance port plugged off at your carburetor, fire the engine up. Your timing at idle (650rpms) should be anywhere between 10°-14° degrees before top dead center (BTDC = Advanced -- Don't confuse Advance & Retarded ignition terms..). Use a timing light while shinning it on the harmonic balancer as the engine is running, to see where your timing is at based at the 10-0-10 mark on the timing cover. The top section of the 10-0-10 will be BTDC, 0 will be TDC, and the below section will be ATDC (After Top Dead Center - Retarded). Advancing the ignition timing is turning the distributor counter-clockwise, and turning the distributor clockwise Retards the timing.
Begin rotating the distributor clockwise or counter clockwise till you're around 10 degrees BTDC according to the flashes of the timing gun, while looking at the timing slash/mark against the timing degree # mark on the timing cover. After getting the idle timing in the ball park, I'll let the engine get to operating temperature, then check it's total timing. To check total timing, rev the motor up around 3000+rpms for short periods of time, and set your total 'Advance' timing somewhere between 32°-36°. If the vacuum advance on the distributor is hooked up, you will have a false reading because the timing will be advancing further, this is why you disable the vacuum advance during this procedure. It's common on a first start-up to be 180° out on the distributor, which will cause it to backfire/not run. It'll let you know that you have to check your firing order, and/or pull the distributor out to rotate the flat blade shaft of the distributor 180°. You can move your spark plug wires around so that they've all moved in a 180 degree circle as well, if they're long enough..
I used to often buy the sun pro super tach 2/II from eBay around $30-$40 and they work pretty good if new, and make sure on the back of the tachometer too that out of the 3 switches 4/6/8 you're on 8 cause it calculates rpms different based on how many cylinders there are. Autometer will have much more calibrated accurate tachometers.
Power Steering Pump LA - Places To Grind For Fit
On my 2nd Magnum Swap, since I went to a V belt setup, I wanted to mount my power steering pump and found that I couldn't make my alternator or power steering work with the newer water pump. I ordered a '86 Dodge ram water pump for a LA 360 to work on my Magnum, but the snout extends too far.. So, I swapped a good LA 273 water pump on my Magnum, while finding out you actually have to have this type of 273 water pump if you want to bolt up your existing 273/early A body V belt accessories. The alternator & alternator bracket bolted up with NO problems at all. Take note on how the newer/later LA water pump's bypass and heater hose fitting are part of the pump instead of removable, like on the early style water pump. While mounting the LA 273 power steering pump, I found out I had to do a little bit clearancing on the driver's cylinder head to make it fit. See pics below..
Below 2 pics show the later water pump that will NOT work with 273 LA accessories.
Harmonic Balancer/Vibration Dampener For LA V Belt Conversion
For a harmonic balancer/vibration dampener for my 2nd 318 Magnum (internally balanced) I went with the SUM-163273 balancer from Summit Racing. I used an air driven impact gun to pull the front crank bolt out which bolts the harmonic balancer on. Then I used my harmonic balancer puller (can rent one from auto parts store) to remove it. On most of these Magnums the serpentine pulley and harmonic balancer are one, 'non separable'. Thus the reason for sourcing a new harmonic balancer with no pulley attached. Next, I oiled up the front timing cover seal, and shaft on the new harmonic balancer. Partially slid it right on the snout of the crank, then used a 2x4 and mallet to give it a good wack/start onto the snout. You can't go wrong putting this pulley on because it's only keyed 1 way. Once in place, I drove it home with the large crank bolt and impact gun (Don't go too crazy). There's actually a torque spec for getting the crank bolt tight properly, but I just kept going till I can't see the dampener moving on anymore, closing the gap between the timing cover. It had like less than an 1/8" from the back of the dampener to the timing cover. I was going to use my '80's truck LA 360 V belt crank pulley that have 4 V belt grooves, but found out it wouldn't work with my upper 273 pulleys because the circumference of 2 of the pulleys are bigger and rub against the upper 273 water pump attachable pulley. You have to understand that there were many different configurations throughout the years in Chrysler's line up of vehicles, different sized pulleys, different length/spacing, etc. So I had to go with my 273 crank pulley that has 2 V belt grooves (one for driving the alternator/water pump, the other for driving the power steering pump). The LA 273 crank pulley only lets you bolt 5 out of the 6 bolts used onto the dampener, which is fine.. But at the time I wanted to have all 6/6 bolted up with the LA 360 crank pulley, just wouldn't work out.
Installing External Electric Fuel Pump
I went with a low psi Holley external electric fuel pump due to no mechanical fuel pump eccentric on the Magnums. If you use one of these electric fuel pumps, you CAN NOT install the pump in the engine bay because it will burn the pump up, it's a pusher, not a puller. I've had a cheaper electric fuel pump before this one, it acted up when installed up in the engine bay. It would over heat, not from the engine heat, but because it's too much for the pump to pull the fuel from the tank from such a long distance and pump it to the carburetor. So I bought this holley low psi electric fuel pump, thinking the cheap fuel pump was bad, but the holley did the same thing when installed up in the engine bay, it would over heat, quit pumping, till it cooled off and begin to kinda pump again till it overheated.. I found out that you HAVE to install an electric fuel pump 10 vertical inches away from the fuel tank. It is much better to have a return line back to the tank so that the fuel pump can stay significantly cooler. They sell fuel filters that have a 1/4" port to attach a return line to, but keep in mind, this may affect the fuel pressure going to your carburetor, depending on how much psi the electric fuel pump is putting out. I installed an electric fuel pump on the frame rail and tied it into the factory 5/16" fuel line. I eye balled and cut a certain amount of the metal fuel line in order to install the fuel pump. I installed the screw-in filter that comes with the pump, and then installed the pump at an angle.. It followed the down/up slope line of the fuel line & frame rail, and it is positioned relatively below the fuel tank so that there should always be some-what gravity fed gas behind the pump.
As I had the pump positioned where I wanted it, I grabbed a small flat blade, then etched in the center of the mounting holes onto the frame rail so I'd know right where to drill. The fuel pump comes with self tapping bolts. Once the 2 holes were drilled out of the frame rail, and slightly big enough to accommodate the self-tapper bolts, I used an angle impact to install the bolts. You can easily ruin the threads of the self-tapping bolts if you don't first drill some holes into the frame rail. The bolts tapped some very short length threads into the drilled holes in the frame rail. Afterwards, I eventually bolted the fuel pump in place, while using the black/negative wire of the fuel pump over one of the bolts to ground to the body. Note, the bolt closest to the top will probably be nearly impossible to completely tighten down with the amount of space given, just at least have the lower one installed, and tight (with a lock-washer preferably). I then installed some fuel hoses on the fuel pump, to the factory metal fuel lines. Because after cutting an X amount of inches out of the factory fuel line, and without a flare, I will use at least 2 hose clamps on the end where the rubber hose clamps onto the fuel line to mitigate any chance of leaks. On my 2nd magnum swapped mopar, for the positive wire of the fuel pump I was pretty meticulous on how that routing went from the back towards the interior, then to a switch. On the first magnum swapped Mopar ('65 Valiant), There's a few rubber grommets that go to the trunk. So I slit a small hole in the center of one, ran a long wire from my aftermarket switch, to an inline fuse, then all the way back, through that grommet and then to the fuel pump. However in my '65 Barracuda with the 2nd Magnum swap, I used a ton of zip ties by zip tie-ing a very long wire going from the aftermarket switch inside, out the firewall, all along the brake line that goes to the rear axle and then spliced it in with the fuel pump. The fuse I used was a 10 amp fuse (ATM/ATC fuse). Only run the fuel pump with fuel, if you run it dry, it wears them out quickly because there is no gas to lubricate the parts inside that do the do..
The holley electric fuel pump in this '65 Valiant that was installed in 2015, is still going strong to this day (11/11/2024). Another cheaper brand I've used in my blue '65 Barracuda lasted only 4 years.. If it sat for an extended period of time I would have to pressurise the fuel tank with air, to force the fuel through the lines & make it prime the pump again to get it working, up until the day the fuel pump completely stopped pumping at a panda drive thru... There's a reason why electric fuel pumps are installed in the gas tank.
Oil Pressure Gauge
It's HIGHLY recommended that you have an oil pressure gauge for any running engine. It's a BAD idea to rely only on the oil pressure dummy light on the dash/instrument cluster panel, because what happens when the light bulb there burns out and you have a real oil crisis going on? Boom..
I went on eBay and bought a cheap, good working electric 2" oil pressure gauge with a sensor/sending unit that screws into the block right by the distributor. The sending unit screws right in place of your dummy light switch, and you simply just wire the gauge to the oil pressure sending unit. You also need 12V to the gauge when ignition is on, so it works.. It's ideal to have 60psi oil pressure (cold). It is NORMAL for the oil pressure to come down as the motor heats up, normal should read around 30-40psi. You want about 10psi of oil pressure per 1,000 rpms. Some of these electric gauges may wig-out with electrical draws from other accessories in the wiring system, so they aren't always completely accurate. However, they are much better than nothing!!
Voltage Meter Gauge
It isn't a bad idea to get a 12 volt meter gauge, so you can see where your battery voltage is while the alternator is charging. 14.7 charging volts considerably is normal. If the system's overcharging, you're at risk for frying electrical components over time, and chancing having your battery literally explode. Out of all the classic Mopars I've owned over the years, every single one in it's life had some unfortunate event of a battery exploding, based off of the battery acid marks that are etched into the bottom of the hood, inner apron/inner fender and front core support, etc. So... make sure you got a Mopar specific voltage regulator, or at least one that charges correctly, and that the body of the voltage regulator is grounded. Make sure that you have a nice thick gauge wire going from the alternator, then straight to battery, and keep an eye on your voltage every now and again. Don't forget to bypass your factory amp-meter/ammeter to prevent future fires from behind the instrument cluster panel/dash.
Water Temperature Gauge
If your water temperature gauge isn't reading correctly on the instrument cluster panel (most don't) then it's also HIGHLY recommended that you get an aftermarket gauge so you know where your engine temperatures are at. The last thing you want is to be overheating and not knowing before hand. These gauges can be found on eBay/amazon as well.
Aftermarket Fuse Box
You can get aftermarket updated ATC/ATM fuse boxes from eBay/Amazon for dirt cheap. I've used them on some builds where the factory fuse block absolutely needed to be replaced due to excessive corrosion. The updated fuse block can be bought with an x-amount of circuits available, typically 6 is what you need. There is a main positive connection on the block to tie your main 12V 'hot' wire from the existing fuse block to, and on the edges of the new fuse block is where you can secure your circuits to. But note, during this conversion you need to pay attention to how the factory fuse block is wired up. At least 3 circuits get power when the ignition is turned to 'on', while the other 2 are constant hot. There is 1 circuit that is left, which is either constant hot or keyed power as well. The circuits that got power from the ignition switch, I used in-line ATC-ATM fuses. Hook your stuff up however you'd like, but please, make it easy for the next owner to understand..
MOTOR MOUNTS
Magnum 318 and 360's are NOT the same on the drivers side... You more than likely will run into this problem '67-'72 swaps. The 318 Magnum has 4 holes on the drivers side while the 360 Magnum has 3 holes, plus, the 360 Magnum's drivers side is the same narrower width just like the LA 360, the Magnum & LA 318's are wider. For '67-'72 cars you CAN still use your passenger side motor mount no problem, same for pre (before) '67 cars if you use a long high grade bolt on the lower 1 hole. The way to correct this for you guys who are 5.9L Magnum Swapping into a '67-'72 car is to buy a set or just the driver's side motor mount for a 5.9L Magnum on Schumacher Creative Services website, or, you may still be able to make the drivers side from your previous LA V8 to work with an extra nut or stack of washers to shim up the distance between the ear of the block to the motor mount. 318 Magnum's drivers side WILL work with early/later LA 273/318 motor mounts. Again, for the 5.9L/360 Magnum & 5.2L/318 Magnum, early/later 273/318 LA mounts WILL work on the passenger side. For pre '67 cars you CAN use your LA 273 drivers motor mount without issue, again, for the passenger side just use a long, high grade/heavy duty bolt to tie in the motor mount to ear perch. Remember, LA 360's & Magnum 360's motor mount ear perches are different in dimensions/closer inward compared to the 318's. If you're expecting your stock LA 360 motor mounts to work on a 318/360 Magnum, they will more than likely not work on the LA/Magnum 318, but should bolt up no problem to the Magnum 360.
I'll probably think of more stuff to write about, refresh this page every now and again to see what's been added or revised! There's so much info here, use CTRL + F on your keyboard to search for specific things, again.
Automatic Transmission Seals & Tips
10-14-2024 -- A side note, rebuilding the TorqueFlite Chrysler 904/727's can be done by yourself. Refer to 'Tom Hand's' book from Amazon:
You will be amazed how relatively easy it is to rebuild one of these units, and save yourself a ton of money down the road, along with a new skill learned!!
A&A Transmissions & Andrews Racing Transmissions is usually where I source my transmission parts from.
I've rebuilt 7x 904 transmissions so far over the last year, and wish I knew years ago what I know now.. Now, getting back to the basics:
Before throwing your 904/727 back in or bolting it back up, it's a really good idea to replace a few seals and potentially bushings. The most important, be sure you replace your front pump seal that the torque converter snout slides & spins against. First, check to see how worn the snout of your torque converter is, if there is a perceivable lip, or even cracks (this is common), it is recommended to have the torque converter rebuilt or replaced. Speedy sleeves are sold to remedy the lip problem, but you will need a larger inner diameter bushing for the front pump by then to make it work. Your local 'TranStar Industries' can take your old torque converter, and ship it off to be completely rebuilt for around $100, as well as have your stall speed altered (to an extent) depending on your application. Ideally, you should replace the bushing in the front pump as well. As this bushing gets worn, it too, can cause a leak, the front pump seal works to an extent on sealing in so much fluid. To keep things relatively simple in this article I may/may not add a more detailed section of going in depth with rebuilding a torqueflite, so with that put to the side.. Assuming your front pump bushing is still good, and torque converter snout is good, we can move forward with replacing the front pump seal. Grab a seal puller from your local hardware/autoparts store as it comes in handy. Carefully hook into the old seal enough to get behind the metal section of the seal, and pry gently. You may have to alternate positions to work it out, be careful not to gack the bushing sitting a little further behind the front pump seal. Once removed, grab your new seal, some manuals will suggest to use a little RTV around the metal ring of the seal during installation.. I just use ATF to help it slide in and let the paint coating do it's job to seal. Make sure the circular spring behind the lip of the seal is nicely in place. Find a correct sized large socket that's able to allow the input shaft to go through the center, or get creative, stack a couple rolls of electrical tape up on top of a large socket, and hammer the seal home carefully into the front pump. Do not compromise the metal ring of the seal, if it distorts the rubber, this can cause a leak.
Before seating the torque converter in the front pump, make sure the snout or at least the lip of the seal is lubed up with transmission fluid, or even better, a little bit of white lithium grease. You can install the torque converter in the front pump by either standing the transmission up, or in it's normal position. There will be 3 initial drops before it's fully seated, and if the mounting tabs on the torque converter to the flex plate are sticking out past the bell housing, that means it's NOT seated. If you over force the matter, it's not hard to get to a point where you can physically break the ear tabs off of the pump gear inside of the front pump. While trying to seat the torque converter, you may have to slightly pull the torque converter outward and rotate it to different positions till it finds it's happy spot/lined up with the front pump gear tabs. I'll usually look inside with a light to see exactly where the ear tabs of the pump are lined up, and then insert the torque converter as such. If I have the transmission sitting in it's normal position, jiggling while rotating the torque converter usually gets it in after some finagle and finesse.. Do not despair, you will figure it out.. Be sure to replace your shift shaft seal, as well as the rubber inner seal that rides against the kickdown lever rod to the valve body, as those are a very common source of leaks. The way I replace mine is by dropping the valve body. If your valve body hangs up during removal, get your drive shaft in the tail shaft (or a spare yoke), slightly turn it, and it will release the parking lock rod. Pop the old shift shaft seal out from underneath with a flat blade screw driver, then lube the new seal with transmission fluid. Pop it in from above using the correct sized socket and a hammer. Do not compromise/bend the metal on the seal during installation. To replace the little rubber kickdown rod seal, remove the c-clip & washer, but leave the rod in place. Take a prick tool and dig out the old seal, then grab your new seal and install it. It will look wrong/upside down because it'll have a groove in the seal, but this is the correct way it is installed. Another very common leak is at the pin that slides through the Low/reverse band apply anchor. Sometimes if you clean the outside area up very good, you can gob some RTV/gasket maker on the end of the pin, and it will stop the leak. The proper solution is to pull the pin out and replace the o-ring (some will have 2 groves that take 2x o-rings), but this means you have to remove the tail shaft housing, plus the pan of the transmission to gain access to the pin.
Check to see how much slop there is back n' forth with the yoke of your driveshaft inserted in the tailshaft, keeping in mind that your u-joints could be worn out as well (replace them if needed). If it's excessive (this is usually uncommon) while moving the yoke up/down while inserted into the tailshaft, then the bushing that the yoke rides against in the tailshaft needs to be replaced. Bushings can be sourced from A&A Transmission, Rockauto, and other places. To replace the bushing, stand the transmission up with the bell housing on the ground. Take a flat blade screw driver and tap around on the ring edge of the outer metal part of the tail shaft seal to work it out. Remove the speedometer gear. Remove all 6 tailshaft housing bolts, remove the 2 large philips screws securing a cover, use large snap ring pliers to open up the snap ring, and then pull the housing off. You may need to gently persuade it off with a mallet. Rent a bushing driver set from your local autoparts store, find the correct sized bushing driver, remember how/where the old bushing is positioned inside, and drive the old bushing out. Grab your new bushing, test fit it first on your yoke before installation, I have found 2 very slightly different sized inner diameter bushings before (we're talking thousands of an inch difference -- ATP vs Pioneer brands), if it's too snug or won't slide on, try taking some emery cloth to the new bushing, or source a different one from another brand.. Lube the outer portion of the correct sized tail shaft bushing up with blue loc-tite, then drive it home in the same position the last bushing was installed so the oil feed hole is in the correct spot (using a larger bushing driver). Reinstall the tailshaft with a new gasket that is lubed up with a light layer of grease. You will have to spread apart the large snap ring again while wiggling the housing back on. If it's still a struggle reinstalling the tailshaft, here's what I would suggest. With the old tail shaft seal removed, take a rag with a pair of vice grips and attach it to the tailshaft, then slightly pull upwards to allow the snap ring to snap back onto the support bearing. Next, dab a small bit of RTV on the threads of your 6 bolts that bolt the tail shaft up to the transmission. You can use a new cork style gasket on the tail shaft snap ring cover, or, get an updated snap ring cover that uses an o-ring style seal from Andrews Racing Transmission. Go snug on the screws. Take a look at your speedometer gear, it will have a number on it that will correspond with a range for where your speedometer housing is supposed to be clocked in at.
Lastly, replace your tail shaft to drive shaft seal. Lube the inside of the seal up with ATF, and also make sure the circular spring is in place. Take a large socket that fits nicely, and drive the seal home into the tailshaft housing. Next, clean everything up as best as possible, replace the filter on the valve body & pan gasket. Make sure your transmission cooler line adapters are snug so they don't leak, I like to use teflon tape here. If you find that your dip stick tube leaks and no new O ring around will do the job readily, simply get some high temp RTV and gob it around that area of the tube, make sure you got a clean surface on the tube and also in the hole of the trans so it'll adhere better, use brake cleaner to make the surface absolutely clean. It's best to do this when you don't have transmission fluid in the pan, let it setup at least a day before adding fluid, with the tube installed.. This has worked for me in the past, but I would strongly recommend sourcing the correct sized o-ring as it will do the job easily without sealers. Also, DON'T forget to bolt the dipstick tube back up to the bell housing - to the motor. Same goes for the bolt that holds the tube to the trans if you got the older setup there (usually 1969-down).
An awesome tip for getting a firmer 1 - 2 shift out of your 904/727 is to take out the big accumulator spring that goes between the valve body and servo piston. This spring helps soften shifts, which is not quite ideal for the longevity of a transmission as it lets your kickdown/2nd gear band slip slightly more during the 1-2 shift. You actually want firmer shifts, which will create less heat on the friction material at work. By removing this spring, you speed up the process of the kickdown/2nd gear apply servo applying the band - doing this is referred to 'knocking granny's head off', especially with a well setup shift kit. Source a clean 3" long (Has to be about 2.952" long) 3/8" extension and insert it underneath the accumulator piston, so that it blocks the piston in an upwards position/about rests against the valve body. The reason you insert a blocker rod underneath the accumulator piston is to keep the piston from moving/slamming back down into the valve body during a shift. If your application isn't going to be seeing any crazy horse power, then leave the transmission alone, and make sure your kickdown adjustments are absolutely correct. See that yellow spring in the pic below? Throw it in the garbage, or keep it if you use a performance shift kit down the road and don't want a fairly jolting healthy 1-2 shift.
Rear Axles
I'm still using the 7 - 1/4" rear ends with 2.76 gears (highway gears/stock) in both of my Magnum Swapped 318 cars and they're holding up just fine, even with some fun burnouts, but I intend on throwing in an 8 - 1/4" or 8 - 3/4" rear end later on. As long as the 7.25 doesn't get traction or hook during a burnout, the gears inside should last surprisingly quite a while. Inspect everything that holds your rear suspension together, u-joints, bolts, nuts, bushings, etc. It's important to make sure everything is in good shape and torqued to spec. Polyurethane bushings are a must these days, as just about any rubber made suspension parts will NOT last anywhere near as long as how stuff was manufactured years ago.. Do what you can do under your set budget, and don't get too carried away building up a rear axle that is overkill for the application in mind.
Driveshafts
If you can, upgrade your small u-joints to the larger style u-joint, or at least use a spicer non-greasable u-joint as they are stronger. Don't cheap out on u-joints, make sure you measure yours and know exactly what you need, there are slight differences out there that will drive you crazy.. I have not had very good luck with buying u-joints from o'reillys lately.. Most haven't fit like they should. My small block Magnums have a tendency to be harsher on the smaller u-joints and sometimes cause on/off excessive vibration while out on the road. Inspect your u-joint straps to see if the bolts are in good shape. A lot of the time the lock-washers on those small bolts are worn out and need to be replaced to help keep your u-joint strap bolts from backing out over time. Blue loc-tite helps a lot here as well. If you are upgrading to super stock leaf springs, keep in mind this may affect your pinion angle of the pumpkin and cause pre-mature wear on the needle bearings in your u-joints (same goes for excessive burn-outs). The common Mopar u-joints out there are the 7290, 7260, and 1310. There are conversion u-joints available as well, so say if your 8.75 third member/pumpkin's yoke uses the smaller style u-joint, but your driveshaft uses the larger u-joint, this style of conversion u-joint adapts both to work together, and it's reverable! See Dr. Differential's website for more.
Brakes
I'm still using the 9" drums all around on the '65 Valiant with the first Magnum Swap, they work ok, disc brakes are a much better setup obviously so I look forward to converting the fronts later on, my 2nd '65 Barracuda has 10" drums all around which are way better than 9" drums, but also intend to swap the fronts to discs on that car as well.. For early A body disc conversions from what I've researched, you can get the conversion kits from SSBC brakes, or wilwood. They even have disc conversions that'll fit over your stock 9" or 10" spindles. As far as the upper and lower ball joints go, they should come with the conversion kit, if not, You can use '73/'74 types that'll bolt right up, but they typically need the bigger upper & lower ball joints.
Early 2024, I got a phone call from my buddy who bought this very same white magnum swapped '65 Valiant back in late 2020. It was a day that I feared, that tragedy struck... Late at night, he got off an exit from I-15, went to hit the brakes to slow down, and immediately found out that the pedal went straight to the floor. He lost all brake line pressure because of a brand new failed wheel cylinder from rock-auto. The main single pot brake master cylinder was still in place (it had been replaced before as well), unfortunately, it was never updated to a dual master cylinder. The original 7.25 rear end to that car got replaced with another 7.25 at some point, and the emergency brake cable wasn't hooked up either.. With the limited amount of time he had to react, he dropped the transmission right into 1st/low and swerved back n' forth to bleed off as much speed as possible, but sadly, the intersection ahead already had a red light. He smacked hard right into an uber that was traveling across the intersection, sending the driver to the hospital from mostly the wind getting knocked out of him. The passengers inside the uber were ok.. My buddy in the Valiant had messed up knees from hitting the dash, at least he was wearing a seat belt at the time. The entire front end of the Valiant was bashed in pretty bad, the frame rails were bent, and none of the doors would open/shut correctly anymore. The insurance totaled the Valiant, and it was the end to a legend. Thankfully, the magnum drivetrain now lives on in a Dodge Coronet of theirs.
There is a reason that in 1967 the government made it mandatory that all car manufactures would have to switch over to a dual master cylinder, so that in the event that there is a brake failure, at least you will have half of them working instead of none at all. If your car still has a single pot master cylinder, please consider upgrading it vs betting it's going to save yours or someone else's life. See on 'The Early Valiant Barracuda Club's' website tech center for converting your ride to a dual master cylinder.
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Mechanical fuel pumps on a Magnum
There's a site suggested on magnumswaps website that sells an eccentric to bolt to your cam shaft if you choose to go V belt style & want a mechanical fuel pump (Scram Speed? Believe Hughes Engines sells one too). On my 2nd Magnum swap I thought about this and did quite a bit of research only to find most people saying the aftermarket made eccentric adapter was engineered poorly or simply doesn't work, but some still saying it works for them. I just got a mechanical fuel pump block off plate from JEGS since my 2nd magnum swap was converted to a V belt style pulley system, and got another low psi Holley electric fuel pump. Electric fuel pumps are very good at keeping a constant supply to the fuel bowls of the carburetor.
HEI all-in-one Distrubutor NOTE for LA V8's:
Something that needs to be noted about the HEI all-in-one distributor, there's 2 different versions in height, usually found on eBay. One has a longer shaft, and the other with a shorter shaft. The short shaft will NOT work with a later LA 2BBL intake manifold because the runners of the intake are designed differently/sit closer towards the distributor, and, the short shaft version will interfere with most bigger oil sending units you install. It's better to get the longer shaft version for clearance, but the longer shaft version may also come in contract with later A-body wiper motors. This was something I noticed as I was fixing to throw my short shaft HEI distributor on my LA 318 in my '74 Duster -- So I guess in all actuality, you shouldn't have this issue on the Magnum AirGap intake manifold with either version, other than just the oil sending unit accessories portion being problematic with the short shaft version.. A tree splitter adapter to screw into the block for an oil sending unit and/or accessories, such as a fuel pump switch, would be an ideal thing to have when using the shorter shaft distributor for clearance.
RECOMMENDED PARTS RECAP
Here's a list showing all the parts I talked about above in this article + some that weren't listed.
- Edelbrock Intake Manifold AirGap 7577
- Oil Pan off Summit Racing - sum-g3536 (Usually out of stock nowadays... See JEGS version, or just get a car style LA-360 oil pan off eBay/wherever)
- Water pump - GATES 43034
- Thermostat - Gates 33509
- Edelbrock 1406 Carburetor (600cfm Electric choke style, 1405 is manual choke)
- Mopar Magnum Valve Covers
- Dorman Air Conditioner Bypass Brackets 34178 (RNB-34178) <- Optional
- Bypass hose - Gates SX6229
- One piece Magnum oil pan seal - DNJ PG1142
- Engine gasket kit (NOT an entire gasket/seal kit) - FELHS9898PT1
- Double Row Timing Chain - TC3028
- Thermostat housing replacement - 902-318
- E3 spark plugs - E3.48 (for Magnums), and E3.46 (for LA's)
- Lokar -- Kickdown cable - Lokar KD-2904HT -- Throttle cable - TC-1000HT -- Lokar SRK-4000 Stainless Steel Throttle Cable Bracket And Springs Kit (Kickdown).
- Chrome oil dipstick - SP7172
- Mid-sump oil pickup tube (See MEL-72-S2 on Summit Racing)
- Wix Oil Filters - Long 51515 - Short 51085
- 904 Transmission's front pump seal - 12070
- 10" LA-273/318 + 318 Magnum (non-weighted/internally balanced) X shaped flex plate - FRA303
- Autometer gauges - I'm making a special mention of this companies gauges for they're highly regarded in quality & accurate functionality, if you want the best gauges, Autometer's where they're at.
- More to come...
NOTES
April 21st, 2017 -- I drove my 2nd 1965 Plymouth Barracuda down to Mopars At The Strip near Las Vegas a couple weeks ago, the 2nd 318 Magnum held up great!! Round trip was over 1,000 miles. I did however have a problem with fuel starvation 3 times on the trip. The Holley electric fuel pump mounted 10 vertical inches away from the fuel tank on the frame rail was heating up and would eventually stop pumping, had to pull over 2 different times to let it cool off and continue on. The next morning I swapped a spare on for the travel back home, it happened again only 70ish miles into the trip back. I figured that if I kept my speed between 60-65mph instead of 70-80mph (70mph is 2,700rpms w/2.76 gears fyi) it would put less demand on the fuel pump, therefore make it run cooler. Thankfully, that was most likely the case since I got back with no more problems. I believed that the sending unit pickup screen is clogged, which would make the electric fuel pump have to work harder to pump gas freely. The car still has the original gas tank, and possibly fuel sending unit, so will be replacing both shortly and am betting it will fix the problem, weird how that never happened going 70-80mph on the way to Saint George Ut where I stayed at a relatives to head to MATS the following morning and back to SG with no problems, just the 2nd run/day to MATS and back. Besides all that, it was a very awesome experience to drive my 2nd Magnum Swapped Mopar to this event, was very fun at MATS this year 2017.
LATER A BODY MAGNUM SWAP -- 1973 PLYMOUTH DUSTER 360 MAGNUM
2/4/2018
I've embarked on my 4th Magnum Swap into my 1973 Plymouth Duster with a 360 Magnum. There's a few things that have been different for me while going through this process and I will be writing up about what's been done so far to it soon.
Update 9/16/2018, I traded the '73 Duster for a '74 Scamp earlier this year and never ended up firing the 360 Magnum up in that car, however, after selling the '74 Scamp recently, I'm funding another 360 Magnum build for my '74 Duster and will post updates + some of the same challenges I went through with the '73 Duster, here.
LATER A BODY MAGNUM SWAP!! 6TH MAGNUM SWAP IN A 1974 PLYMOUTH DUSTER! 10/18/2019
So I've finally got around to Magnum Swapping my 1974 Plymouth Duster I've had sitting around since December of 2016. Pulled the tired LA 318 & 904 over the winter of 2018. There were a few little things that were different going through this process I felt it be worth mentioning here to help you guys out with later A bodies. So, main key points I'll cover is header installation, fuel pump installation, battery relocation, etc.
HEADER INSTALLATION
For this ride I bought Summit Racing ceramic coated headers, not just for looks, but to also provide an advantage for lowering engine heat temperatures significantly, which helps make things under the hood last longer and allows the motor to breath just a bit better. I had Dougs non-coated headers to begin with, they were smashed pretty bad on drivers side more than likely from speed bumps and torsion bars set too low. So with the 3" collector exhaust still there, unbolted from the old headers, I had undone the idler arm from the k member, swiveled it over in line with the center link, and also undone the inner tie rod end next to it in order to slide the driver's header right on in. I only replaced the inner tie rod for now and bolted the idler arm back up, when removing them, a small sledge hammer helps a ton, you can sometimes get lucky just smacking the outer portion of the center link to release the the tie rod, other times you'll have to find different methods for removing them. I like to undo the castle nut, flip it around and thread it on just a little, and smack it. If I'm planning on saving the tie rod end, I won't use a pickle fork as it will destroy the rubber grease boot.
So with the drivers header in, I set the passenger's header in place, and left both there NOT bolted to the exhaust until they were bolted to the engine first. Use a couple bungee straps to keep the headers from sliding down in your way when installing the drivetrain. Leaving the headers completely unbolted during the whole Magnum Swap process helped a TON by getting the starter in, trans lines, etc. Now keep in mind if you have stuff that you think might not be good next/near the headers due to heat, it's recommended you get some heat shielding tape or wrap, would recommend this for the mini starter big time.
Use a couple zip ties to hold the header gasket on, makes it sooo much easier, and make sure the bolt holes are aligned. So once the drivetrain is all bolted in and everything's hooked up to your satisfaction to where it won't be a pain to install anything else as the headers are bolted in, proceed to bolt up the passenger header, as the gratification you'll receive for how easy it was will prepare you mentally, spiritually and physically for what's about to happen on the drivers side. Do use a floor jack down on your headers if needed to help get the bolt holes more aligned to get the bolts started into the head, make sure ALL are started so you have some wiggle room to get the next one in.
You will find it is rather quite a P.I.T.A to get the last 2 header bolts in towards the firewall on the drivers side because all manufactures for "lower priced" headers can't seem to figure out or care how to make your life easier by adding some more clearance or more slight bend recesses next to the header tubes in order to get the bolts in without much of a fight. Take a (I think it was 1/2", whatever size your header bolts are) wrench you don't really care about, cut it in half with a grinder, and you'll be able to tighten that last darn header bolt with much more ease next to the firewall. So once the fight is over, step outside, admire whatever view you have for a while, maybe walk over to the fridge, and then relax. Next, get your header collector hardware and gasket, and bolt up the headers to the exhaust. I thought about using rtv gasket maker on the header gaskets and collector gaskets to help really seal them up, but didn't, and it worked out perfect when I fired it up. So that's basically how to install headers in a later A body.
Electric Fuel Pump Installation
For installing an electric fuel pump I went with a low psi mr.gasket fuel pump. What was different this time is the factory fuel line layout compared to early A cars. I ended up deciding to put it on the out portion of the frame rail where you can see it behind the tire on the passenger side. There's either a vent or return fuel line that runs next to the main fuel line feed, so I bent both around and upward that used to follow the bend of the frame rail as it initially bent around, cut out a 8" section and installed the fuel pump. To mount, I grabbed the right sized drill bit that was slightly smaller than the diameter of the bolt threads, then ran the correct sized tap through the holes to give threads as the self tapping bolts didn't work out. Once installed, I ran a 12v wire all the way to my aftermarket relay box and added an inline fuse to the pump, the relay is tied into the ignition switch. Do not use teflon or any thread sealer on the fuel pump main filter as you screw it in, gas will melt that fast and gum things up quick. So that's how the fuel pump installation went on the Duster!
BATTERY RELOCATION
Since I didn't have much luck sourcing a Ram Van power steering pump that sits lower and allows you to keep the battery up front, the battery had to go to the rear. Bought a universal battery box, 25ft of 0 & 4 gauge automotive welding wire, painless main disconnect switch, and plenty of ring terminals + battery clamps. I chose to have the battery placed in the trunk on the passenger side with the theory of spreading the weight so there's not so much on the left/drivers side, especially when you are sitting there that it would affect cornering.
Bought some 1/4 - 20 bolts, washers, lock washers and nuts from the hardware store. First drilled 4 holes in the universal battery holder bucket, then marked them to the trunk floor and drilled 4 holes. Once it was bolted down, I started running the wires from the back to front. So I picked the positive post of the starter relay as my main power source for the front, and also added an additional starter relay next to it with a bridged + wire to add more connections as I ran out of threads on the first, plus it's a good idea to have a backup anyways. I added RTV/gasket maker later between the main + post of the starter relay and the solenoid wire that bolts on right below just in case if the nut ever comes lose and one of my hot + wires comes in contact with the solenoid wire, it won't spontaneously engage the starter, just like tripping both with a flat blade screw driver to bypass. I still used the standard starter wire, just cut the battery terminal off and added a ring terminal, then sandwiched it between the 0 gauge wire and 4 gauge wire. Probably would've been perfectly fine if I had just ran a 0, but was thinking I'd have the 4 gauge wire go from alternator all the way back to battery, and figured it made more sense to jump the alternators new charge wire right over to the starter relay to save more wire.. Either way.
Ran both the 0 and 4 gauge + wires to the main disconnect switch that I mounted to the tail panel, and added another set of 0 & 4 gauge wires to the aftermarket battery terminals. You'll want the best grounds you can get since the battery's in the back now. So I used a brush grinder to get a spot next to the battery box down to bare metal, added another bolt there with a 0 gauge wire for the negative side. For up front, did the same thing and ran the wire from inner fender over to one of the bolts that holds the AC delete bracket on. Also attached the factory negative wire on the firewall, passenger side over to the rear valve cover bolt.
Right next to the front's main negative wire that's bolted to the inner fender, I added another long bolt, this time 3" away and the bolt pointing outward into the wheel well so I'd have a lengthy amount of threads to add more negative connections to with ring terminals. I was pretty serious this time on how I did my wiring compared to the '65 Valiant's, had to go back and replace some wires and fix connections already due to using splices, no electrical tape, and just being in a rush back then in 2014, it really doesn't take long for connections to get corroded over time.
Take your time to do it right the first time! There's heat shrink connectors I like to get from eBay, you add both ends of wires and over lap them in the middle of the connector, then use pliers to crimp the metal ring in the center, and use a heat gun on the heat shrink to make it seal n' keep moister, corrosion out. Consider adding inline fuses to your new connections that pass through the firewall or go all the way back to the trunk, just in case in the event any thing happens your car doesn't burn to the ground. I also use electrical tape around all my new connections when I'm done working on them. That's pretty much how to relocate a battery to the trunk and wire it up! Hope this helps!!
3/13/2022: It's been a while since I've been back here on the site, planning on revising & adding some new info once again so stay tuned!
3/15/2022: Back in 2020 I snagged a 1966 Formula S Plymouth Barracuda that had a cracked block LA 318 installed. Long story short, sourced another 318 Magnum from a '90s manual dakota. Essentially did the same conversion over again and swapped it into the barracuda. There's a few things I'm going to talk about during the process of that swap. (More pics to be added soon..)
Serpentine belt system.
I utilized the serpentine belt system in this Mopar without an AC delete bracket, plus had manual steering from factory. To do this, I used my old serpentine belt tensioner pulley in specific to replace the idler pulley since I had already bought a new tensioner that came with a new pulley installed, as most should.. The special bolt washer had to be ground down on the washer portion to match the exact diameter of the bearing of the old tensioner pulley, that way it would be bolted up fine and still allow the pulley to spin. After a couple experiments with some serpentine belts, I found this belt 'Premium Multi-Rib 555K-7' in specific was the perfect serpentine belt to use. You can measure what belt you think you will need for your setup simply by using any automotive wire and wrapping it around your pullies in the same configuration the serpentine belt would be routed, it can be a bit tedious but it works. However, you have to remember to equate how far your tensioner travels as you're maxed out by using a wrench to see what your tension distance is, about 2" usually. So for example, you figure you'll need a 62" belt after measuring with your wire, but really it needs to be 60-ish" for the tensioner in the equation. Now, if you get a belt and it's slightly too long or too short, but may just get by, you can re-clock the tensioner's position in the bracket by drilling another set hole, 're-clocking' your tensioner, had to do this a few times with good success. It's nice going this route since it takes out another pulley to not worry about for future maintenance, and has no issues with tension. That's it!
Map gas is your friend when stubborn bolts won't come out, but use caution on what you're using it on. Plasma cutters are better if the bolt can't come out, had to do this on a caliper bolt that somebody managed to completely round the large hex head off in the past.. DON'T USE 12 POINT SOCKETS. Also use standard sockets instead of metrics, loser sockets cause problems. For whatever reason, Chrysler used quite a bit of metric hardware on these Magnums, more-so on the accessories bracket stuff.
Please feel free to leave some constructive feedback on this article or even message me if you have any, would love to improve however possible!
Don't cheap out, get a mig welder with 25%Co2/75% Argon gas, and throw that crap harbor freight flux core welder in the garbage!
Don't do this...
Websites that I recommend
Magnum Swap - (no title)
Schumacher Creative Services 'Engine Swaps' - Schumacher Creative Services
Summit Racing - Fast Free Standard Shipping on Orders Over $99 at Summit Racing
JEGS - JEGS High Performance Parts | Aftermarket Auto Parts & Accessories
eBay - Electronics, Cars, Fashion, Collectibles, Coupons and More | eBay
RockAuto - RockAuto
The Early Valiant & Barracuda Club - EVBC
The 1962 - 1965 Mopar Web Site - The 1962, 1963, 1964, 1965 Mopar Web Site Welcome Page
TTI Performance Exhaust & Headers - http://www.ttiexhaust.com/Shipping-Ordering/OrderingInfo.htm
SSBC Brakes - SSBC Performance Brake Systems
AMD Auto Metal Direct - Correct As Original Restoration Parts for your car or truck project.
Auto Body Specialties - Autobody Specialties Inc
Classic Industries - Classic Industries | Restoration Parts | Mopar Parts | Camaro Parts | Firebird Parts | Nova Parts | Impala Parts | GM Truck Parts | Tri-Five Chevy Parts
Layson's Restoration - LAYSON'S RESTORATIONS - DODGE, CHRYSLER, PLYMOUTH RESTORATION PARTS
Year One - YEARONE Classic Muscle Car Parts | Chrysler, Chevrolet, Pontiac, Mustang, Buick, Oldsmobile, GM Truck, Tri-Five, Jeep
Hot Rod/ Mopar Muscle - Mopar Muscle Archives - Hot Rod Network
MSD - MSD Performance Products | Tech Support: 888-258-3835
Autometer - AutoMeter Gauges - Quality - Accuracy - Built in the USA
My go to local automotive stores are O'Reilly & AutoZone.
Thanks for reading, hope this helps! Mopar or No Car.
This article was originally written up back in September 21st, 2016. I will continue to periodically update and revise this article as time goes on. Last updated - 12/18/2024.
DIY MAGNUM SWAP!!
Back story
DIY MAGNUM SWAP!!
Back story
I purchased a relatively clean all original white 1965 Plymouth Valiant 200 back in 2014. An interesting story goes along with how it was acquired.. I was at the checkout at a scrap yard back in January 2014, buying some cool '70's Dodge hub caps for a '73 slant six Valiant I once owned in high school. I just happened to have my head turned slightly towards the window out front, and watched a white ratty '65 Valiant for the first time go down the road on a car trailer! We chased the owners down, eventually worked out an amazing deal, and later towed it back on home. It had an LA 273/4.5L Small Block V8, with an old cable-shift style torqueflite 904 transmission. She initially ran and drove, but it had no brakes at the time. The brakes were eventually fixed, along with a few other things, and I drove the Valiant all around for several months during my senior year of high school.
I also have a blue 1965 Plymouth Barracuda that's been in the family for over 20 years now. It's painted Maaco blue from the 80's, and had a later 1974 slant six drivetrain that I swapped in, back in 2013. I test drove the barracuda once after getting it going again with the '74 replacement slant six engine, since the original/factory one to the car was seized. Right away after the first test drive, I decided it wasn't enough power for me.. So the next day I wasted no time and pulled the whole 273 V8 drivetrain from the white '65 Valiant. Threw it all in the '65 Barracuda 1 week before graduating high school, achieving my long goal for driving the Barracuda there before the end, and embarking upon a crazy new life shortly right after graduation!
The '65 Valiant sat and sat, and after a few enjoyful months of driving around the Barracuda I ultimately decided to go with a different direction with the barracuda's 273 drivetrain due to a problem.. Sadly, the LA 273 began to smoke/burn oil, more than likely due to not having lead in today's gas + non-hardened valve seats.. The valve stem umbrella seals were also more than likely rock hard as well. I had a decent 40 over rebuilt LA 360 V8 engine I pulled from a 1986 Dodge W150 truck + a 2WD 727 transmission that I had intended to throw in it. But unfortunately, the wind blew the tarp up exposing the 360 engine to the sprinklers, so that idea got scrapped.. After searching a bit on the local classifieds towards the tail end of summer 2014, I found my first 5.2L/318 Magnum. With intentions, hopes, and ambitions high, I removed the Valiant's original 273 drivetrain from the Barracuda. Next I separated the valiant's original 904 transmission (cable shift/push button type) to use again behind the magnum, then, converted the 318 magnum to a carbureted setup and swapped it right into the Valiant! That's all in a nutshell...
The Barracuda was later magnum swapped in 2020 with a low mileage 360/5.9L Magnum. I still currently own the blue '65 Barracuda (owned 20 years strong now!), a magnum swapped '71 Satellite, '73 magnum swapped Scamp, '73 magnum swapped Duster, '66 magnum swapped Barracuda, '83 Magnum swapped CMX Dodge Mirada, '71 Hemi swapped D100, and an '81 Z28. I eventually gave this ratty 1965 white Plymouth Valiant 200 to my brother for him to enjoy for a while, up till it got parked for a while.. We bought this car in 2014, kept it until late 2020, then sold it to a good friend of mine. In 2022, we started to drive our classics over to our local car meet every Saturday/Sunday night, and it was a blast to race side by side with the Mopar I once owned! Still, blowing away the tires and going faster than any of my rides at the time, there was something special about this first Magnum Swapped Mopar.
In early 2024, the Valiant's life suddenly came to an end in a tragedy related to the 'single pot master brake cylinder'. If your ride has one of these, please, do yourself and everyone a favor and upgrade to a dual master cylinder. Make sure your emergency brake is hooked up correctly. I cover more about what happened to the Valiant further down this article under the 'Brakes' section.
11-13-2024 - A side note about myself
Since 2013 I've gone through about 30+ Mopars, completed well over 20 Magnum drivetrain / V8 Swaps, along with many torqueflite 904 transmission rebuilds/builds, and so much more related work with classic cars. I think it's important to preserve these rides, and to keep them alive out on today's roads. The feeling you get behind the wheel of an old classic is unmatched towards anything new made now, especially when you can throw a more modern V8 in one within a reasonable budget and feel that torque!! The fun never gets old.. So, that's pretty much my back story, now let's get onto how I did my first Magnum Swap in an early A body, a 1965 Plymouth Valiant!!
THE MAGNUM SWAP
Magnums are usually found in 1994-2001 (some 2002-2003) Dodge Ram's, Dakotas, Vans, Jeeps, and Durangos, an easy pick from the junkyard or online ad. A couple ways to figure out which is a 318 Magnum or 360 Magnum is to look under the driver's cylinder head. Right on the side of the block you will see the casting numbers, it'll consist of random numbers - ######## - 318 or 360. Or, look for factory stickers under the hood. The harmonic balancer from a 360 typically will have 3 open large slots/look larger, and uses a jaw-style puller to remove the balancer. While the 318 will look more solid, and uses a steering wheel type harmonic balancer puller. One of the best ideal ways to check to see if a Magnum 318/360 from the wrecking yard is most likely good or not, is to attempt to move the crank pulley by hand, or using a 1 - 1/4" socket on the crank bolt to turn it over. Make sure it'll turn over completely several times just in case, it's also easier to move the crankshaft over with the spark plugs out, beware of crud in spark plug tubes though. Also, do a quick inspection externally of the block itself, make sure there's no holes in the block & rods showing through of course, or cracks that are quite obvious (doesn't happen often).. Make sure there's not an excessive amount of rust in the coolant system as well, and mixed oil/antifreeze. You're mainly looking for a freely rotating engine, but this does not guarantee that the rod/main bearings, etc, are in good shape.
Another great thing to do is to buy an inspection camera for your phone off eBay. You can inspect the inside of the cylinder walls to see how everything looks. If you see cross hatches on the cylinder walls, it'll indicate a very healthy motor, if you see very glazed cylinder walls or lots of scoring, that could mean a few different things - 1. It could've over heated in the past - 2. Lots of miles/possibly not maintained well, etc. Inspect the tops of the pistons if you can, and check for pre-detonation (Usually looks like the surface of the moon, ok, maybe not that bad..) From my experience with these Magnums, it seems as if they don't care if they have very high mileage, such as 200,000+ miles. Typically they won't start smoking out the exhaust till around the 300,000 mile mark. Ultimately, it depends on whoever took care of it during the life of the vehicle it was in. What gives a major advantage with using these engines is originally having a tall overdrive gear behind the engine for all it's life, plus being fuel injected, and better sealing ring technology. Less rotations/lower rpms equals less wear, compared to the older days with your typical 3-speed 904/727 auto transmission (plus some 3-spd manuals). The magnums will have better cooling jackets, roller lifter valve trains, better flowing heads, better oiling systems, etc.
Now, some tech about automatic transmissions. If you are swapping from a slant six car, your 904 transmission will NOT work with any V8 as the bell housing & starter location is designed different (if manual, switch the bell housing). You have to get a specific small block V8 904 or 727 small block transmission, the 727 is beefier & can handle 600+hp stock no problem, it's also a bigger transmission both physically and internally. Be cautious when searching for a small block 727, as most of them out there are for big blocks. The 727 bell housings have very subtle differences, do a google image search to see the differences. Also, to tell the difference between a 727 & 904 right off the bat is to look at the oil pan shape, as well as the collar on the 904 at the bell housing. A lot of the guts in a slant six 904 compared to the V8 904 are interchangeable. Keep in mind however, the slant six 904 will have 3 friction discs instead of 4 in the clutch packs. Magnum & LA V8's have the same bell housing mount pattern.
An A-999/A-998 transmission is an A-904, but just a beefier version with an added extra clutch & steel plate in the high gear clutch pack direct drum. Approaching the 80's your A-999/A-998 torqueflites came equipped with low gear sets, mainly to combat with the lower horse power engines back in the day from the 80's, as well as heavier cars. The low gear sets in these transmissions can make a huge difference in your 1st & 2nd gear ratios if your rear gearing is between 2.45 - 3.23's, and you're putting out under 350hp. The A-999 will be a lock-up transmission, meaning the torque converter will have a large clutch inside to physically connect the input shaft directly to the crankshaft of your engine to lower the rpms, because a standard non-lockup torque converter will always be slipping. The A-998 will be the non-lockup transmission, just like a standard A-904, but more heavy duty (again). For those with higher HP builds, A-904 with 4 standard friction plates in both direct & forward clutch drums is plenty sufficient. You don't need to compensate with adding an additional friction in the direct drum to make it 5 'forward' "thin" frictions in the direct drum, just use a good shift kit with high line pressure, such as TransGo's TF-1/TF-2 shift kits, and your torqueflite will be golden.
If you're looking at building a mild or stock setup V8, stick with the 904 as they can handle up to 400hp stock + can be built to handle even more power (as high as 900hp with the right parts from C.R.T Racing/A&A Transmission). Shorter gears inside from the 904 compared to the larger 727 = more power to the rear wheels & it's also a lighter transmission in weight. For those of you with slant six cars, sticking with a 904 transmission will enable you to use your stock drive shaft as it's usually the same length from /6 to small block V8. The 727's tail shaft is much longer & uses a bigger/different spline count slip yoke. To put it shortly as well, the 904 is a safer transmission compared to the 727. The 727 usually needs a bolt-in sprag, in case in the event the stock one fails, it'll help lessen the chance of the large direct 727 clutch drum from exploding. When the sprag fails, depending on how high the rpm of your motor is at the moment of failure, times that by about/around 2.5x is how fast the direct drum will end up spinning, at which point they can/will come apart. Billet direct clutch drums are also sold to save your feet/legs. Scatter shields won't always protect you, look up '727 explosion - barracuda' and you will understand why. There's not many instances recorded out there of 904 direct drums exploding because the rotational mass is much smaller in comparison to the 727, and Chrysler used some pretty big ol' rivets to hold the over-running clutch/sprag in the case.
The #1 failure in Chrysler automatic transmissions is either not having your kick down adjusted correctly/not hooked up (seen this too many times..), and too much HEAT. Make absolutely sure that your kickdown settings are as close to a true 1:1 ratio with the throttle, from idle to W.O.T. If using a kickdown cable, make any necessary modifications to your kickdown lever at the transmission if needed to achieve the correct geometry/funtion, it matters. An external transmission cooler mounted in front of the radiator is ideal & highly recommended for the longevity of your transmissions life. Hooking it up to the radiator like the factory does is still fine, if the transmissions not seeing a lot of crazy high power & torque constantly. But beware, if the radiator's internal trans cooler ever fails, you can have antifreeze & ATF mix together.
Something that needs to closely be pointed out.. Say if you were doing this swap in a B/C/E - body, those cars are much heavier than the A body platform.. So take into consideration how much harder a 904 transmission has to work to move those cars, more heat generated will usually be a resulting factor. Many B-bodies still came with 904s from the factory (unsure if C-bodies ever did), but a vast majority were also small/big block 727s on the B/C/E bodies. Once more, it's always a good idea to invest in an external trans cooler, as well as a good shift kit for your valve body so your shifts are crisper. Shift kits also help the transmission stay cooler with less slippage between shifts, this saves a lot of life on clutch/band material over time.
Now back to the Valiant's Magnum Swap. -- Please bear with me about the format with all the back & forth in this article, it's still going under much revision, just like a project! 11/15/2024. -- Also, please make everything you do look neater than what you see in some of these pictures below, what you're seeing is early stuff when I was learning years ago..
When I first got the 5.2L/318 Magnum for the '65 Valiant, I decided to do away with the stock fuel injection and go carbureted for simplistic reasons, less wires! The first thing I did was document/take pictures all around of the motor, then began to clean it up.
Clean up
I used a metal scraper to get chunks of grease off first, then used a couple cans of Gunk engine degreaser from the autoparts store. I power washed it in the driveway with long cloth material from work (work at a print shop, 28x40" industrial presses, used, used impression & blanket washer rolls) on the ground to catch the chunks of junk flying off the motor. Made sure I had stuff I didn't want to get water in blocked off for the most part. Then used the air compressor to blow excess water out of various spots. After everything was dry, I bought 2 cans of high temp VHT Hemi Orange spray paint from the auto parts store. Shot the motor, let it dried, and then began to take the stock fuel injection stuff off.
Stuff ordered
Before I got too crazy disassembling stuff, I had to figure out what I needed. First thing I ordered was a re-gasket/re-seal kit. Thermostat - 195° Fahrenheit (Gates 33509) -- 180°F is better if you aren't using fuel injection. Since I decided to go with a carbureted setup, the intake manifold would have to be changed. I bought an Edelbrock 7577 AirGap intake manifold off Summit Racing (When it was cheaper...). The Edelbrock 7577 intake manifold has the intake bolts going vertically instead of at an angle like on the LA motors, so it's the perfect fit on any stock magnum engine. However, much, much more affordable airgap intakes are now manufactured from various companies/sellers on eBay, they work on LA + Magnum V8s and still flow great! For a carb (fuel make it happener), a friend of mine sold me an Edelbrock 1406 (600cfm) 4BBL carburetor. The edelbrocks work really well, and are simpiler to work on compared to most carburetors out there. I had to source a special bracket made by edelbrock to bolt onto the carburetor throttle lever, so I could still use my stock kick down linkage & throttle cable. This part is the Edelbrock 1481 bracket, and it can be bought from the autoparts store, ebay, amazon, or summit racing. I had to pull the nut & kickdown piece off the previous 2bbl carburetor from the 273 V8, to bolt onto the new edelbrock 1481 bracket for the kick down rod to snap onto.
Most people will buy a Lokar kick down cable kit to do away with the hassle of adjusting/modifying stock kick down linkage. There is a detailed subject that I cover about how I installed my Lokar throttle cable and kick down cable further down this article.
For an ignition system I decided to go with an HEI All-In-One Distributor. Using this type of distributor required new female end spark plug wires to work. So I went onto MSD's website, searched for the small block Magnum 5.2L/5.9L spark plug wires and bought those. The part number for the MSD Street Fire spark plug wires I bought is - #5532. You can still use the stock magnum spark plug wires as well, but my original magnum wires were toast. The LA V8 distributors have female type spark plug sockets, and male posts on the magnums, just like the HEI distributor. For spark plugs I went with E3 spark plugs, the part number for these spark plugs are - E3.48. The advantage of having the HEI all-in-one distributor is you get a much hotter spark, + no more ballast resistor - just a 12V ignition wire tied into the existing ballast resistor harness wires, and the ignition coil sits inside on top of the distributor. Plus there's a simple tachometer terminal/connection right next to the ignition connector.
Update 2/19/2017 - The HEI distributor decided to start failing after nearly 2 years of using it in my 2nd Barracuda, am switching to the MSD 6A ignition box with a new stock distributor + MSD Blaster 2 Coil, don't expect to have anymore problems after that. I am assuming it began to fail because it wasn't seeing a consistent 12V upon startup from the existing old ballast wires, this could've been fixed with a 12V relay. ---- 3-13-2022, from another source in regards to cheap HEI distributor units, they claim the advance timing springs/weights may be faulty and partially activated at idle, along with another issue involving the bushing on the shaft. Essentially leaving 30-40hp on the table, while a set of new springs could help resolve the issue. Don't cheap out on ignition systems, buy them from a reputable company such as Summit Racing.
Update 7/24/2018 - I am still experiencing ignition issues in my 2nd '65 barracuda, even with the fairly new MSD setup, swapped to a 6AL box, no difference, swapped to an old stock electronic distributor, no difference, changed alternator, voltage regulator, still no difference, acting like its sometimes firing off all cylinders and then 6-7, will be unhooking the main firewall harness to see how dirty/corroded the contacts are, could be responsible for pulsating voltage between 13v-14v & ignition troubles. ---- 3/13/2022, pulsing voltage problem has been partially isolated to the voltage regulator ground, pulsed less when a negative wire was ran from the negative battery terminal over straight to the body of the voltage regulator (upgraded to the '70s adjustable VR), but what really seemed to help was wiring a 4-pin relay that would bridge direct 12V power to the VR, over to the positive side of the battery, acting like a voltage sense wire for the voltage regulator, 'in a sense'..
(Above pic is of my 2nd '65 Barracuda when it still had a 273, clear cap and rotor bought separate off eBay)
I thought about going with headers but found out TTI headers cost a fortune on early A bodies, but there's a more vast header selection for the later A bodies because in '67 they widened the shock towers for more space + ease of throwing big blocks in, so I stuck with stock LA exhaust manifolds. You can run Magnum exhaust manifolds, it's a little bit of work for fitment, but it can be done, and they flow so, so much better. On the driver's head of the motor towards the rear, some material needs to be ground off so the exhaust manifold will seat flush to the head.
Since I decided to keep the stock serpentine belt set-up, I found out that I needed an AC delete bracket pulley which they sell on eBay or Summit Racing --
Dorman Air Conditioner Bypass Brackets 34178 (RNB-34178)
When I got the AC delete bracket, I noticed rather right away that it wouldn't bolt up to my accessories bracket because the hole mount spacing's are different between a 'Ram van' motor and a 'truck', so I headed on over to the local pic-a-part junkyard to pull an accessories bracket from a '94-'01 Ram truck to make the AC delete bracket bolt up. Note how I had to cut out a 2"x 2" square on the accessories bracket for the heater hose fitting to fit/work on the intake.
Update 7/24/2018 - My buddy pointed out my serpentine belt wasn't long enough and that it wasn't wrapped around the idler pulley, which of course caused slipping later on (didn't quite realize that at the time), corrected that issue with the AC delete bracket. You don't need an AC delete bracket if you can get the correct sized serpentine belt for manual steering cars & route it correctly. You don't need it for power steering cars either if you can figure out the correct sized belt, and, route it correctly. In fact, you really don't need it at all, I'm just here to inform you how to install it, just, bolt it on, or don't.
I ordered a later style ('70s) new voltage regulator & special 2 wire bulk head connector in order to use the magnum alternator, very easy to wire that up. Don't buy a cheap Chinese voltage regulator, specifically look up 'Mopar voltage regulator', it'll be black with white/yellow text, shaped like a rectangle and have a triangular connection with 2 little posts, they're made in the USA and will charge correctly/last sooo much longer. They will lessen the risk of over charging your battery then having it explode, yes, that can happen.. When you install the voltage regulator, make sure you have a PERFECT ground surface, so take the time to get some of the black wrapping off one of the bolt holes on the VR. I just ran a ground wire from the negative post of the battery right over to the bare metal potion on the VR. When sourcing the special VR plug connector, search 'Mopar voltage regulator connector' on the interwebs.
It doesn't matter which color side of wire you choose, green or blue, for example we'll go with blue. The blue wire ties into the ignition system (Best to hook up at ballast resistor harness wires since it's the main ignition source), then take some extra wire, hook it up to one, of the 2 FLD posts on the alternator. Then hook the other end of the wire to your ignition harness as well. For the green wire, take a long wire, hook it up to your last/unused FLD post on the back of the alternator, and splice the other end in with the green wire on the Voltage Regulator. Get about a 12 gauge thick wire (or thicker) about 2 feet long, hook it to the BATT. (Charging terminal) post on the alternator, then hook the other end up straight to the battery's +/Positive post.
4/30/2017 Update: The Mopar VR has been charging between 13.4-14V in my 2nd Magnum Swapped '65 Barracuda with no problems.
I DON'T recommend using your existing factory alternator BATT./charge wire because the magnum alternators typically put out higher amps compared to an LA - V belt driven style alternator. You could risk causing an electrical fire because there's an ammeter/ampmeter on the back of the instrument cluster panel that can only take so many amps. The factory ammeter/ampmeter was never a great section of Chrysler's wiring in the majority of their cars, and were often the culprit of burning, many, cars to the ground. Those 2 thicker gauge wires back there commonly get hot enough with a higher amp alternator, to start melting, then ground out. So going straight to the battery in this case between the alternator & + post, bypasses that ammeter so your electrical system is much safer. You will need to either go under the dash, or partially remove your instrument cluster panel to tie both the thicker gauge red & black wires together (both are positive wires). They are hooked up to your ammeter/ampmeter (the gauge that says D - C), just snip the ends, and join the two. Source an aftermarket 12V gauge to monitor your voltage.
Since Magnums don't have a mechanical fuel pump eccentric or hole in the magnum timing cover for mounting a fuel pump, I went with a low psi Holley fuel pump from summit racing. There's a variety of the low psi electric fuel pumps out there, the most common is the dead-head style, meaning there is no return port back to the gas tank. A lot of these type of low psi electric fuel pumps usually have a self-fuel pressure regulator built in.
I discovered having a magnum out of a ram van has an advantage for making the magnum power steering pump work better in any A-body, because the pump sits significantly lower compared to the dodge trucks version. This made it so I didn't have to relocate the battery to the trunk. I went to the 'house of evco/house of hose' to have custom power steering hoses made in order to work with the magnum power steering pump, over to the factory power steering box.
MAGNUM POWER STEERING HOSES - 2/2/2018 -- I found out that there's this little factory adapter that is usually screwed into the power steering box for a female end PS hose to screw onto. As I was looking at the PS box on a 1973 Plymouth Duster, I noticed there wasn't one there. (Working on my 4th Magnum Swap with a 360 in that car). So quite literally all I did was remove the PS high pressure hose (both male ends) from the LA 318 PS pump, hooked it up to the Magnum PS pump, and everything WORKS!! So I can't quite 100% verify that if you get a 1973 high pressure power steering hose, it will be the one you need, because the LA 318 I pulled came from a 1984 Dodge Truck, so that hose could very well be from a 1984 PS high pressure hose. Your low pressure PS hose should hook right up no problem as well as it's just standard 3/8" line. Make sure you use specific power steering hose and not fuel line, because the power steering hose material will be able to handle the high temperatures that move through the power steering system.
While I was helping my buddy work on his 1971 Plymouth RoadRunner with a 318 Magnum Swap, we found out that the power steering hose he bought specifically for a 1971 Plymouth RoadRunner wouldn't fit into the power steering box. Along with the 7/16" to 1/2" factory adapter removed, because that end of the hose required a 1/2" male end to screw onto, not 7/16". So he found a 1/2" to 1/2" adapter that screws right into the pump like the other adapter, got it ordered from O'reillys site, and it all should work out. The other end of the high pressure hose still screws into the Magnum PS pump with no issues.
10/18/2019 - PS STEERING HIGH PRESSURE HOSE
So on my 6th Magnum Swap in a 1974 Plymouth Duster, here's what's going on with the Magnum power steering high pressure hose situation. On another '71 RoadRunner, I used a new 1973 A body high pressure PS hose, and it would never seal right at the magnum PS pump. I couldn't ever figure it out till I finally looked closer and saw differences between both tube flares on the Magnum style & LA/old style high pressure lines, that bolt into the back of the PS pump. Wish I took some pics to show here, but there's a normal flare on the 73 PS hose that would seat perfect in it's factory LA pump, but, the Magnum requires a different flare style.. I would call it a ring flare because the tube is straight at the end for maybe 1/4", then there's a ring in the metal that's barely thick. It goes straight right after that to the rubber portion of the hose. What's weird is, I bought yet another new '73 A-body LA style high pressure PS hose for the '74 Duster's 318 Magnum Swap (with a magnum pump), installed it, and somehow it's not leaking. So maybe it's by chance the wrong flare/LA style flare can find a happy spot to seal in the magnum PS pump. The same hose configuration, again, in the '71 RR with a magnum PS pump, would simply not seal. So, if you get a '73 A body/Duster high pressure hose, it may or may not work for you. You could, also have one correctly made at a local specialty shop that deals with high pressure hoses/fittings.
I bought Mopar Magnum valve covers off eBay (back when things were more affordable..). Had to buy an oil filter angle adapter + special bolt that has oil passages & comes with gasket + washers, from eBay. For an oil pan since all magnums have the truck style oil pan, I went to summit and bought a sum-g3536 oil pan, essentially it's an LA 360 car style mid sump oil pan. LA 273/318 oil pans will NOT work on any Magnum motor (I have about 2" of oil pan clearance to center link with this new Summit oil pan). Typically, on LA oil pans there's factory dents in the pan for the center link to clear when maxed out on the turning radius. The oil pan mentioned above won't have any issues, the center link will naturally put a small dent/recess in the new pan over time with driving, so you'll have a good center link turning clearance. I also had to order a new mid-sump oil pickup tube (See MEL-72-S2 on Summit Racing).
If you are magnum swapping into a slant six car, early or later A body, you will need a V8 center link for oil pan clearance. If, for whatever reason you still find yourself with the lack of oil pan clearance, you can attempt to shim your motor mounts up with thick washers. Slant six people, you can try this and maybe get by using your stock center link without swapping to a V8 center link, but, this is only applicable to pre '72 cars since in 1973 they went to the spool type motor mounts.
For later A bodies, you DON'T have to change your K frame out if your car is a slant six, simply go to Schumacher Creative Services website for V8 conversion motor mounts. Early A bodies share the same K frame between a slant six and small block V8 - Schumacher also makes motor mounts for Big Block swaps in early and later A bodies, heck, they even make slant six conversion mounts if you want to go backwards in performance! They have just about everything you'd need. Trans-dapt also sells more affordable motor mount conversion kits that can work decent in '67-'72 slant six A-bodies.
I re-used my stock LA motor mounts from the previous LA 273. The casting of the passenger motor mount ear on a magnum V8 is flipped around, compared to the LA 273/318. You can however, still make it all work with a long high grade 8 bolt -- Read my thread below about this.. That being said, something important to take note is between an LA 273/318 and an LA 360, the motor mount perches/ears are different in dimensions, usually the LA 360's is more narrow. On the Magnum 318/360's however, they are the same, only on the passenger side, those dimensions are also based off the LA 273/318. It's only the passenger side that is flipped around/mirrored on the Magnums in comparison to the LA's. It would also be ideal to make or get a torque strap that ties the block, to your K-member, so it puts less stress on the motor mounts overtime.
Small block 318/360 Magnum Swap - Motor mount answers for those with questions
I bought a Champion 3 core aluminum radiator, and failed to take notice of which side the water pump faces, so I had to combine 2 radiator hoses and an exhaust pipe to couple them together along with hose clamps, it still works just fine, just looks a little goofy. For a cooling fan setup I decided to go with an electric fan, mounted in the front. Also bought a $10 chrome car-style oil dipstick tube. The magnum water pump I bought is the GATES 43034.
The Magnum Swap progress
Before swapping the intake manifold, all the intake bolts were soaked in WD-40 (PB Blaster is better) because they are notorious for breaking upon removal. Typically, it's the 4 outer corner intake bolts that like to snap since they are exposed to the elements. This happened to me on a 2nd magnum swap into my other '65 Barracuda unfortunately. I had to use a cheap flux welder to weld bolt ends to the stud of the broken bolt, and out they came! I undid all the old intake manifold bolts very carefully, then pulled the bee hive intake off. Another great tip when removing the intake bolts is to use MAP gas to heat the bolts up a little, then smack the tops of the hex heads with a hammer to help shock the threads free from crud holding them in place, and then carefully use an impact gun if you have one. It can sometimes put less stress on the bolt when removing the bolt vs the full straight force of one's arm strength. When I got my new dual plane Edlebrock airgap intake, I was surprised to see how only 2 water jacket crossovers would be used instead of all 4. Apparently, this is fine to have the rear ports/crossovers blocked off. The center exhaust cross overs are completely blocked for obvious reasons, and thankfully, they don't exist on the Magnum heads!.
I proceeded to clean the surface where the intake manifold meets the heads really good with a straight edge blade. Make sure you have clean lint free rags or plastic bags in the intake valley to catch junk. Have a shop vacuum on one hand as you get the excess junk removed with the other hand. They say to not use the front and rear 'china wall' seals that come in your gasket kit for your intake manifold, because it can still cause leaks. Use some high temp RTV (gasket maker) and run a nice 1/4" bead across those surfaces + in the corners, and smear some around your 4 square head water jackets. Then move forward with installing your new intake manifold gaskets. There are NO intake dowel alignment pins on magnums. I like to take 2x spare long bolts with the same thread pitch as your intake manifold bolts, then cut the heads off and use them as an alignment tool. Once the new intake is in place, take a mallet and tap around the intake to help seat it in place, make sure your gaskets aren't moving around a bunch. There's a bolt down sequence you're supposed to follow, look it up on google images. Be very careful when you torque the old intake manifold bolts, they can snap really easily. I'd say just go snug and a bit more if you don't use a torque wrench (this is what I did after reusing the old bolts). After other instances of breaking the old magnum intake bolts after re-use, and having to go through the hassle of removing the intake just to clean everything up again, I will always use new grade 8 bolts from the hardware store. Shim them up with extra washers if needed, and torque them to spec. With new intake bolts, go through the torque sequence multiple times as the bolts will 'work themselves in' each round.
Next, I drained all the oil out of the oil pan, and let the RTV/gasket maker setup for at least an hour on the intake manifold before I flipped the engine upside down. Once flipped, I pulled the pan off, and cleaned the deck surface up really good. Should've pulled the rear main cap off to replace the rear main seal at the time but didn't... Make sure you do. If you do, make sure you off-center your rear main seal halves slightly by at least 1/8" as this provides a near perfect seal. Pay very close attention to how the lip of the rear main seal is supposed to face, and use the plastic looking installation tool provided in the kit, so the sharp machined surfaces of the block doesn't gack up the seal during installation. When putting the main cap back on, be sure to oil up the bearing a little. Put the cap back onto the block, carefully work it back & forth till it seats flush. Snug up the main cap bolts, insert the front crank bolt, tap it with a hammer, and do the same on the back of the crank as this helps re-seat the bearing. Then torque the rear main cap bolts to spec and move on to the next step!
The new oil pan from summit racing arrived, and I found out that you can still use the magnum (leak proof) one piece oil pan seal! If it looks like the rear piece of the seal won't seat on the pan, it will, it'll stretch itself around the pan when bolted down. Sometimes when you get these new oil pans, the flat surfaces might be slightly bent, but, they will flatten out when bolting the pan down to the block. I will usually put a little bit of RTV/gasket maker in the corners of the oil pan before putting the seal on, as well as the corners of the timing cover + rear main cap corners. Watch closely that the oil pan seal stays where it's supposed to when installing the pan, because sometimes the front large lip of the seal likes to suck itself in. The truck magnum oil pickup tube was swapped out for a car-style mid-sump. It's shorter in length, and closer to the crank for the new/any LA 360 car style oil pan to work.
Threw the new one piece seal on the pan, put the pan on, bolted it down & torqued it to spec (or just pretty snug..). Once again, if you find your new oil pan's sides are slightly bent from factory, they will usually straighten themselves out as you bolt it down to the block, no problem. Double check that your drain pan bolt is snug!!
I flipped the motor back up again, then replaced the valve covers & gaskets, and forgot at the time to do some grinding work on the driver's cylinder head, so that the LA exhaust manifold can sit flush. We'll cover this next..
The above pic was from removing the Valiant's 318 Magnum again later on. The old front pump seal of the transmission lasted a few months before it completely failed and was puking excessive amounts of fluid. While everything was out, I went back to grinding some material off of the driver's cylinder head so that the exhaust manifold would seat flush and not leak. See the bare metal showing on the driver's cylinder head? That's where you have to grind some material off. Now back to the initial magnum swap.
Before I bolted up the early style 904 cable-shift transmission, I still wanted to use the stock magnum flex plate, however, the LA 273 flex plate would've bolted up no problem.. 1-2 of the holes on the magnum flex plate that mount onto the torque converter needed to be slightly drilled more open in order to get everything to bolt up correctly. At the time I failed to realize that the PILOT of the torque converter was smaller than the pilot hole in the back of the crankshaft. The pilot is back nub of the torque converter that recesses into the back of the crank shaft. I still managed to bolt the early 904 torque converter up, unfortunately, slightly out from truly being centered up. This was most likely due to having the slightly 1-2 flex plate TC mount holes opened up more/not keeping the TC 100% centered up. I probably should've just used the LA stlye flex plate at the time. The pilot is responsible for centering the torque converter up on the crankshaft.
This article is focused on automatics, as I do not have experience with manual transmission setups. As the transmission is already bolted to the engine, and you are at the point of bolting up an 'early' 904 torque converter.. Use a crow bar to gently pry the TC upwards and center it up in place. Install 1 bolt at a time, and only go snug. If more than 1 hole won't line up, this means that you are off on the rotational bolt pattern. Spin the torque converter to the next hole till you can get all 4 to bolt in. Then, use some spray paint to mark one of the TC bolts to flex plate & torque converter so if you need to remove everything in the future, bolting the TC back up to the flex plate will be much easier (you could do all of this before bolting the trans to the engine and save some hassle). Sometime between '67 and '68 they changed the crank shaft pilot hole size to a bigger circumference.
To this day, the torque converter appears to still be slightly out of round while rotating. This could mainly be because of the pilot of the torque converter being smaller. Not lining things up properly when bolted to the magnum flex plate that has 1-2 holes slightly drilled more open as well. Or, this may also be an illusion because of the spray paint used to mark 1 torque converter bolt.
Side note, fast forward nearly 10 years later (2024), I tore apart this early 904 transmission and found hardly any bushing wear in the front pump, and the snout of the torque converter looked untouched, which is good!
Some important things to note -
LA 273 & LA / Magnum 318's are internally balanced, meaning, there are no counter weights added to the flex plate or harmonic balancer.
However, the LA 360/ Magnum 360 is externally balanced.
A lot of LA 360's usually have a large weight welded to the torque converter for external balancing purposes, while the 360 Magnum usually has weights welded to the flex plate. According to Magnumswap.com, you CAN NOT use an LA 360 harmonic balancer or LA 360 flex plate with weights on a Magnum 360 (same applies if the torque converter has a large weight welded to it), because, they're balanced different externally from each other. On the 318 Magnum/LA motor there are no counter weights on the flex plate or harmonic balancer because they are internally balanced. However, that doesn't mean that any torque converter won't have some smaller extra counter weights added to them, in fact, most TC's will usually have smaller weights added to balance the torque converter itself.
If you are running a 360 Magnum, sometimes, you can remove the harmonic balancer pulley to swap over to a V-belt style, often times, both the harmonic balancer & serpentine belt crank pulley are attached to each other permanently. In that case, it may be worth making a trip to the wrecking yard to find one that are separable, or, go to summit racing for a specific 360 Magnum harmonic balancer (if you are planning on using V-belt accessories) if not, continue to use the serpentine belt 360 harmonic balancer for the serpentine driven accessories. Another thing to mention, it's recommended to use a little bit of blue thread locker/loc-tite on the flex plate bolts and torque converter bolts.
Again, pre '67/'68 TC's/Crank shaft pilots will have a smaller circumference. Don't forget, LA 360's and Magnum 360's are balanced differently externally, from each other. You can NOT throw an LA 360 flex plate/harmonic balancer on a 360 Magnum, otherwise it will cause excessive vibration. You can however, make the stock existing magnum flex plate work! Which is something I'd highly recommend re-using on the 360 Magnum, since there are already external weights in place. If for some reason you don't have a flex plate, go on summit racing's site to order the correct flex plate for the 360 Magnum, or make a trip to the bone yard. The flex plate from summit is usually moon shaped, so the cutout on those flex plates are what makes the external balancing work. LA 360's are externally balanced in two different ways on the rear section. The flex plate, or, a large weight welded to the torque converter. If, you are swapping from an LA 360 to a Magnum 360, make sure you knock the large weight off of your torque converter if you have one to re-use the torque converter.
The one thing that just about killed me on this swap was not replacing the FRONT PUMP SEAL before swapping everything in the first time.. It is the main seal that goes into the front pump, around the input shaft (usually has an orange/red color to it). If you have the chance while the transmission is out, do not hesitate to replace the seal(s), or rebuild it! They're easy.
Remember to seat the torque converter in the transmission's front pump correctly. Do not slide the transmission onto the torque converter with the converter bolted to the motor.. While you are installing the torque converter, will drop further into the front pump at least 3 times to be completely seated. It can help using something to bolt to the lower bell housing and push against the torque converter to help it stay in place and not slide out while moving the transmission about.
Next, I bolted just about everything essential up to the magnum, but the serpentine belt system, and then took it off the engine stand. The transmission was re-mounted afterwards.
I bought an engine lift plate that bolts onto the intake's square bore, where the carburetor would be. I've found using a set of carburetor studs that will only be used to lift engines works the best. Some of the thicker removable washers that go over exhaust manifold bolts work great over the carburetor lift plate studs. Next I used my wonderful (crap) 1 ton engine lift, and had an awesome friend around with me to help out. We pulled the hood off the Valiant, moved the motor with transmission attached into position, and moved the car towards the drivetrain while I began to lower it. What I've found over the years during the process of installing drivetrains is, if you use the closest hole on the engine lift plate towards you, it will angle the drivetrain nicely downward during installation. Then, you can swap over to the middle or rear hole as needed after you find a good resting spot to sit the drivetrain down, while, using a floor jack on the tail shaft of the transmission.
Note, there's a firewall lip that the ball n trunion (1965 & down automatics) adapter/tail shaft has to jump across. At the time, my buddy eventually had to hop on in and stand on the transmission as it went in to achieve the angle needed for installation. Once cleared, swoop, right on in it goes. Make sure to have good weight added to the back of the engine lift if the legs don't extend out far. Usually 2x 12V batteries does the trick, or a person on the back, if they don't jump off of the lift to help... You CAN make this all happen without removing the hood, it is a tight squeeze, but doable! Sometimes it's easier to install the drivetrain with the car high up in the air on jack stands. For those with the later 904/727 (1966 & up automatics), try to not gack your tail shaft seal boot when installing the drivetrain. You can zip tie a rag over the seal to protect it from the sharp edges of the firewall lip, and keep it away from any crud in the area that may want to enter the tail shaft during installation. Quick tip, wrap a rope or something at the end of the tail shaft to get the angularity needed as you pull the car towards you during installation, while pulling a rope at the same time.
I noticed things weren't looking right with the motor mounts, then found out they were backwards/on the wrong sides (common mistake).. Swapped sides and right on in it went. I loosely secured the motor mounts with the thick motor mount washers & nuts, to allow for wiggle room when bolting the transmission cross member in place. At this point while the drivetrain is slanted downward, it is the most ideal point for installing your transmission cooler lines, kickdown cable, etc.
When using a Lokar kickdown cable, I like to leave the 1 tail shaft bolt a little loose so that if it comes in contact with the floor of the car, it has some room to move. Don't forget to snug that bolt back up later.. Then, use a floor jack on the tail shaft (or pan with a 2x4) of the transmission to lift it up more level. I will usually have the early biscuit style transmission mount already bolted into the cross member, then, slide everything into place to bolt the transmission mount/cross member to the tail shaft. With the later spool type mount, it's best to have the mount bolted to the tail shaft, and then slide the cross member in place. Leave the two tail shaft to transmission mount bolts a little loose for further adjustments when installing the cross member, then snug everything up when ready.
Those with kickdown cables:
Pay close attention to how your kickdown cable operates, remember, you need about a 1:1 ratio between the kickdown & throttle (from idle to WOT). On the early A body cars, sometimes your kickdown lever comes in contact with the floor. You can make clearance by recessing the floor further in, or try slightly bending the kickdown lever, or trying using another lever. I like the kickdown levers that point closer to the bell housing. If you have enough length on your kickdown lever, you can, drill additional holes as needed to achieve the proper kickdown to throttle ratio.
This is a critical part to the longevity of your torqueflite's life span.
Those who are going to use the factory kickdown linkage:
The way to adjust your kick down linkage correctly is, lengthen your kick down cable/rod, open your throttle just barely until you start to feel the kick down pressing the throttle pressure rod on the valve body, and you should be set. Once more, you basically want a 1:1 ratio with the throttle and kick down, so when you're just barely pushing on the throttle, the kick down lever should already be pressing the throttle pressure rod on the valve body (go to the point of when you start feeling resistance). You may have another adjustable rod to play around with right by the firewall. There is some normal room of kickdown adjustability for making the shifts occur sooner, or later. Having your kick down/throttle pressure set right is VERY IMPORTANT to the longevity of your transmission's life.
Some people out there will think it's ok to disable the kick down/leave unhooked. However, doing this WILL burn your transmission up, because the clutch packs/kickdown band inside won't be pressed firmer together for minimal slippage as you're driving, especially while getting on the throttle. Manual/Reverse manual valve bodies will NOT have a kick down setup, because they are full-time line pressure.
Once everything was all said and done, she was a SLEEPER.
This build was done for around $1000, every penny spent was well worth it. They're very fun and torquey motors with lots of life left in them! It's hard to kill a Magnum V8. Keep on reading for more important information with Magnum Swapping your ride!
More info
2015 I bought a 2nd 1965 Plymouth Barracuda (Chocolate frosty colored) - see my thread...
1965 Plymouth Barracuda - 318 MAGNUM V8
Also, back in late 2015 I traded my 1974 Plymouth /6 Duster for a 1966 Plymouth Barracuda 273 Commando - thread on that car is here...
1966 Plymouth Barracuda - Commando 273 V8
Fall of 2016. -- I just recently got done with my 2nd magnum swap on my 2nd '65 Barracuda. I had to get my 904 push button/cable shift type transmission rebuilt because I had lost reverse but still had all gears in drive, that was kinda my justification for doing the swap since the trans had to come out anyways. The barracuda had a healthy roller 273 from 1967. I got the 904 rebuilt, hooked it up to my 2nd 318 magnum, swapped it back in, and what do ya know, it doesn't have reverse or even 1st gear! I had my transmission guy put a shift kit in it but some reprogrammer rod from the kit wouldn't fit, so 'most' of a shift kit was installed. Turns out, the cable shift 904's/727's have quite a few differences compared to the 1966-up units.
I tried a couple different things with the valve body, pulling it out, adjusting the line pressure, adjusting the kickdown band, putting the VB back in (several times), it got old fast. I eventually pulled that old cable-shift transmission back out for the last time, and decided to use a later 904 that came from a 1974 Plymouth Roadrunner. My transmission guy is currently swapping the new guts he threw in the old 904, into the newer 904. pre '66 904's are very problematic. It mostly sucks having to constantly keep an eye on the shift cable adjustments, plus, the ball n trunion driveshaft was a bad setup from the get-go.
Update 2/5/2017 -- Got the 2nd Magnum swap build finished, hauls A!!. I ended up getting a B&M ratchet star-shifter to install in the Barracuda so it would work with the later 904 transmission. Already had a slip yoke driveshaft made to work in it. Will further update my thread about this Barracuda pretty soon.. With this magnum swap I decided to go with the V belt style for that nice classic old-school look, and it's working pretty good so far! I used an LA 360 timing cover, bought a fuel pump block off plate, kept the LA 273 water pump so I could bolt the LA alternator up with ease, plus have this water pump for the future use my 273 LA power steering setup, if we ever convert from manual. I used the LA - X shaped flex plate. The newer ('66-up) 904 torque converter pilot will fit like it's supposed to in the back of the crank shaft, because it's 1969-up. O'Reilly's has the correct 10" LA-273/318 (non-weighted/internally balanced) X shaped flex plate that'll bolt up no problem on a 318 Magnum - Part # FRA303.
Hope this info helps, post/message with questions, think I've covered it all in this article. Keep on reading for more below! Also, check out my other threads & YouTube Channel full of Mopar -
gwmax11
Mopar or No Car!
Keep on reading - More important Magnum Swap info!
Intake fitting holes/intake bolt down sequence:
Here is a picture of the intake manifold bolt torque sequence. One side is 12 8 3 1 5 9, the other side, 11 7 4 2 6 10. The heater hose adapter size on the front right of the intake is 3/8", next to that on the left is 5/16-18" -- This is where I installed the temperature probe for my electric fan. You can also plug it with an NPT plug - assortment kits are found at the auto parts store. Then on the very left is where the temperature probe goes (1/8"). On the passenger side towards the rear of the intake manifold runner there is a 3/8" threaded hole, just like the heater fitting hole, except, no water goes through here (just air). Plug that with an NPT plug as well if you don't plan on running a brake booster. The bypass to water pump hole size on the intake is 3/4", the large brass fitting comes with intake Edelbrock manifold. If you need one of these large fititngs, usually you have to buy them separate from Edelbrock.. For the heater hose fitting and thermostat housing, I pulled them from the stock magnum fuel injection intake manifold. I cleaned them up with a wire brush wheel on an angle grinder, and painted the parts with VHT high-temp silver paint.
Starter:
For a good starter, I bought a $60 rebuilt mini (high torque) starter off eBay. They crank 2-3 times faster compared to the stock dinosaur-dolphin starter, and use less power when cranking. They are also perfect for the, 'oh crap my engine stalled!' situations. The mini starters give you a lot more room for header tube clearance as well. On my automatic transmission, I left the inspection plate off. Most people will, because they get bent so easily, and then your left with this annoying noise caused by the torque converter bolts rubbing against the plate.
Picture of a 1970's internal dual field Voltage Regulator - Note, this is not a Mopar voltage regulator, this was before I discovered non Mopar voltage regulators had BIG issues, buy one made in the USA!
Breather's and PCV
For a valve cover breather I sourced an Edelbrock brand from the local auto parts store, and it came with it's own grommet to install with ease. For the other side, I used an old PCV valve and snugged it into a grommet. Usually, when you buy Mopar Magnum valve covers they will come with a bag containing 4 different valve cover breather/PCV grommets to use. On my 2nd Magnum swap in the Barracuda, I bought a different style PCV breather that's as big as the Edelbrock breather, which has a snout to slide to still connect a hose. The other end of the hose connects to the front of the carburetor. Grommet sizes needed are about 1 - 1/4"
Throttle cable bracket
For a bracket to hold my throttle cable in place I used my existing throttle bracket from the 2bbl LA 273 V8. The intake bolt size on the Magnums are 5/16" - 18 thread pitch. I went to Lowe's and got a 6" LONG bolt, 2 nut-washers, then pulled 1 intake bolt out on the drivers side in relation to where the throttle cable is, secured the throttle cable bracket on the bolt along with the nut washer, then threaded in the long bolt to a point, then secured the bolt with the 2nd nut washer on the intake manifold.
Update: Get a higher grade & much longer bolt that moves this bracket up higher, so that the throttle cable doesn't put too much downward stress on the throttle shaft of the carburetor. This here currently could cause the shaft to wear excessively over time & create a permanent vacuum leak.
Some bolt measurements
The bolt size to hold any small block mopar on an engine stand is 3/8"-16 (16's the thread pitch) for the top 5 (only 2 will be used, the first 2 away from the top center bolt hole) and recommended 2x 7/16" bolts & nuts (any thread pitch, just make sure the nuts have the same thread pitch for 2 bolts that pass through the lowest 2 holes on the engine), also get a few washers. I highly recommend getting grade 8 bolts as they are very strong. On my setup where my 360 Magnum is currently stationed on an engine stand, the upper 2x 3/8"-16 bolts that thread into the block are 4 - 1/2" long with 20 washers each bolt to take up slack in my combination (40 washers total between the upper 2), the thickness of the washers are 0.055" according to my digital calipers, 16-18 of these washers = about 1". The 2 bottom bolts are 8 - 1/2" long, using 2x 7/16" washers and 2x 7/16" nuts. You can come up with your own combination if you like.. I could've used shorter bolts and less washers but it works as it is for now. A rotatable engine stand from Summit Racing dramatically helps this entire process, you simply spin around a crank handle to change the angle of the engine without needing any help flipping the engine over like on a standard cheap engine stand.
IN CASE you need an extension for your kick down rod, you can buy 2 feet of 1/4"-28 all thread rod from the hardware store/online -- It is the same size of the kick down adjusting rod. A new 2ft threaded rod can be cut to your desired length. For a coupler, you specifically have to type in on ebay/amazon '1/4-28 coupler nut'. Bought some off eBay for around $11. Your existing kick down linkage from an LA V8 WILL bolt up no problem on a Magnum head. Don't forget (for early A body people) you can add more throttle pressure/length to your stock kick down system by also adjusting the vertical middle rod behind the motor. I attempted to use some kick down linkage off a later A body ('74 Duster to be specific) in my '66 Barracuda, and it would NOT work because, the pivot that slides over this little rod, that screws in the side of the bell hosing of the trans, would run right into the stock exhaust system. So I abandoned that setup, then pulled the stock kick down linkage to that car ('66) from my 2nd '65 Barracuda, then threw it back on, and all is well. Again, most people will get a LOKAR kick down cable to do away with factory linkage. This is the route that I went with in my 2nd Magnum swapped '65 Barracuda, along with the Lokar throttle cable. It is pretty easy to hook up and adjust. 'WhoSaidTyler' on YouTube made an excellent video explaining on how to install a Lokar kick down and throttle cable setup. Below you'll find a section explaining how I set mine up.
LOKAR KICK DOWN & THROTTLE CABLE - INSTALLATION
Alrighty, so first off I went on eBay and ordered these 3 individual Lokar items for my 2nd Magnum Swap in my '65 Barracuda - Lokar kick down cable (Lokar KD-2904HT) - Lokar Stainless Steel Carburetor Bracket and Stainless Springs (Lokar SRK-4000) - Lokar Universal 24" Stainless Steel Throttle Cable (TC-1000HT) if you can find a 1ft version that would work just perfect too. These things are getting pricey............
LOKAR CABLE BRACKET INSTALLATION
I got the Lokar carburetor throttle/kick down bracket mounted to the driver's rear carb stud, this can be a little tricky installing. Next I pulled the carb stud out, positioned the bracket in place, then slid the carb stud back through, and loosely bolted it on snug since there's some more adjustments to make. On the Lokar carb bracket, take note of how there's a little threaded stud and nut on the bracket itself right next to the carb, all this does is orients the bracket. You can hook up your return spring setup either way, old school in the front, or how Lokar instructs to install their setup which works great, either way. I wouldn't recommend having both setups because it causes the Lokar carb/throttle/kick down bracket to bend in a strange way, thus causing your cables to become lose over time, I'd recommend doing it the Lokar way. If you're having an issue with your idle being too high and are compensating with too many return springs, double check for vacuum leaks, as well as your throttle cable tension setting.
LOKAR KICK-DOWN CABLE INSTALLATION
Before going any further, when you find yourself at the point of needing to cut/shorten a throttle/kickdown cable, make absolutely sure whatever piece that is supposed to be attached to the cable is already on the cable. The strands can potentially fray out after a cut, and make it nearly impossible to get the piece back onto the cable. There is a trick that sometimes works by taking a small zip tie, and going around the cable strands with the zip tie as it realigns the them once more. DON'T CUT THE THROTTLE AND/OR KICK-DOWN CABLE TOO SHORT.
Once everything was finally out of the pointless excessive shrink wrap, I looked over the instructions carefully. I threw the barracuda on jack stands, then unhooked all of the stock kick down linkage. Next, I used the little hex angle allen wrench provided to undo one of the ends of the cable in order to slide the cable out of its protective sheath. After that I moved forward with mounting the cable sheath to the tailshaft section of the transmission.
Remember as the instructions say, DON'T remove the 'clamped' ends of the sheath, just leave those on there.. Unless you need to slide them up the sheath to trim the sheath down for your application. It's a P.I.T.A to get them back on if you do remove those pieces. So, have the sheath adjuster nuts backed all the way off to the point where you can have just a few threads showing. Doing this will give you more movement of the cable during operation. The kick down cable sheath will have a mount that mounts to the Lokar throttle/kickdown cable bracket. Bolt the mount of the kickdown cable to the backside of the throttle/kickdown bracket. Line up both upper holes for when you install the Lokar throttle cable sheath later. Don't tighten anything up, just go finger snug at this point. Then for the other end of the kickdown sheath, you'll see on the sheath that there's another mount with a bend in it. This mount will be bolted on one of the transmission's tail shaft bolts. When you're looking at the tail shaft bolts, the bolt you will need to remove is the left/drivers side bolt that's 1 up from the 2 lower tail shaft bolts, it's a very tight space on early A-bodies, and sometimes (not always) you may have to pull the transmission cross member out with a floor jack supporting the pan to lower it for access.. I'd recommend test fitting the mounting bracket/cable sheath once mounted, so again, don't tighten the bolt till you've decided if you need to either slightly bend the mount a different way to just barely move it away from the rear transmission cooler line nut, or take a hammer to slightly dent a recess in your trans tunnel a tiny bit for just a little more room to work with (early A body problems yay..).
Once you have it mounted to the tail shaft, have at least 2-3 threads showing on the adjuster sheath nuts there, then tighten them up a bit. Next, slide your cable back in from either the top, or the bottom. The bottom half is better left alone in the first place so you don't have to bother with sliding so many things back on as compared to the carburetor end. When you have the important stuff slid back on the kickdown cable, plus already have the cable installed back in the sheath, start working on the transmission end once again. You will need to remove your kick down lever from the shift shaft of the transmission to bolt up the tiny ball hitch/pivot looking nut. You'll want the ball end facing upwards, but, it can be installed upside down depending on whether it will clear your shifter linkage/cable.
When I remove these levers I'll undo the bolt which secures them to the valve body, then slide a flat blade in between the shifter lever, and wiggle each end till it works it's way up & off. When reinstalling the kickdown lever, you may need to slide the flat blade in between the halves of the lever to open it up a little more for ease of re-installation, because if you tighten the securing bolt too hard, it clamps it tighter.. It will close itself back up on the throttle pressure section of the valve body once the bolt has been snugged back up. Make sure it is snug and that the lever does not loosely wiggle at all, if it does, that may cause a shift quality issue. You may have to slightly bend this lever to barely clear your stock/aftermarket shift rods/cables. In a lot of cases, you may need to get a different kick down lever, as there's a LOT of different kick down levers out there for different applications.
Something I've found when using these Lokar kickdown cables, is that it's better to have a kick down lever that points closer to the bell housing. Because of the the geometric angle at which the cable must pull at, while the cable is already mounted at the tail shaft. This is a critical section to pay attention to so your transmission has as a true 1:1 ratio between your throttle at idle to Wide Open Throttle. You can drill additional holes in the lever if needed to obtain the correct 1:1 window of the ratio, and mount the little ball hitch/pivot piece accordingly. Improper kickdown settings can result in shift quality issues, as well as the longevity/life of your torqueflite 904/727 transmission.
So, once you have that all ironed out, it would be really simple to snap the kick down cable on the shift shaft lever's ball hitch/pivot. Then, reinstall the lever back on the shift shaft section of the valve body. For the adjusting threads of the Lokar kick down cable (at the transmission end still), I went just about all the way out/most slack, but still have up to 3-4 threads of the adapter screwed on. Most of your adjusting for this cable will happen up at the carburetor. Before you pull the car off the jack stands, check everything over again. Make sure your cable isn't rubbing against the trans cooler line nut, check that nothings binding up weird, and that the geometry of the cable looks good (check this when the kickdown is fully hooked up to the carburetor). My recommendation is to hook up a small return spring to the bell housing ear, then over to the kickdown lever so just incase the spring is weak in the valve body, it will fully return the lever to it's resting 0-out spot. Doing this will help mitigate strange scenarios where you are decelerating and feel it shift back into 2nd for a split second while coming to a slow stop. Once you've verified everything's hooked up correctly at the carb end, get the vehicle off jack stands/ramps and move onto the next thing.
Now, for finishing up at the carburetor. Once your Lokar cable is slid back into the sheath, and secure nut, install the other flat looking ball hitch/pivot at the lowest hole of your carburetor's throttle lever, while having the flat ball facing towards you. Then slide/click the Lokar mount piece of the cable onto it. You should have lots of slack at this point. So, here's where you can decide if you want to go with front or rear return springs for the throttle cable, again, I'd recommend the rear Lokar setup since it works great. For installing the Lokar return springs, you'll want your tear drop piece mounted to the back side of the kick down flat ball hitch piece (on the other side of the carburetor throttle lever). Once that's installed, get your return springs and hook them up to the lowest hole of the Lokar throttle/kick down cable bracket. Secure the kickdown carb nut when you find the position you like. Check later if you need to flip your return springs around if they interfere with the high idle cam or anything else that might be in the way.
When you've dialed all that in, move your adjuster set-nut around on the Lokar kick down cable, so that it almost has tension on the kick down lever when you're barely opening the throttle. Too much throttle pressure/kick down tension of the cable can delay the shift, too little will make it shift too soft/not shift or not 'kick down' correctly when you need it to. With the larger nuts securing both sheaths of the throttle & kickdown cables, I like it set where there's the least amount of threads showing (on your left side of the bracket), so that the cables can work more freely during operation.
LOKAR THROTTLE CABLE INSTALLATION
Story time -- Later on, my 2nd magnum swapped 318 began to not quite run right when I was still using the factory throttle cable setup.. It acted like it had a vacuum leak of some sorts. Someone informed me with how I had my stock throttle cable positioned at an angle, which can put excessive stress on the throttle shaft itself. In turn, it will wear out the bushings of the carburetor body, and cause a permanent vacuum leak. So I found it reasonable enough to get a LOKAR throttle cable to go along with the Lokar kick-down cable setup. Not only for this reason, but for smoothness of pushing down the gas pedal. I could have just got a longer high bolt to let the stock throttle cable mount sit higher, but then it would most likely run right into the Lokar throttle/kick down bracket.. So, once my Lokar throttle cable arrived I went and studied how everything works with the old stock throttle cable setup.
The factory throttle cable sheath from inside is secured with an interesting looking C-clip that's usually a fight to pop off. I used a thin flat blade screw driver to persuade it off. The bottom black plug that helps keep the cable attached to the throttle pedal bracket, was removed to remove the throttle cable. Out everything came.
I found that the securing nuts of the throttle cable sheath itself were too small compared to the hole opening of the stock throttle support firewall plate, therefore, I had some thinking to do. I removed the firewall throttle pedal assembly plate, then found a washer the perfect size. I welded it on with my cheap harbor freight 120V flux welder, and it was exactly what I needed to get the job done. Note: After thinking about this later on.. you don't have to go to this extent with a welder.. Using larger washers and securing the nuts of the Lokar throttle cable sheath is enough to get the job done right.
On the Lokar throttle cable, just like the kick down cable, remove the lokar cable from the sheath, starting at what would be the carburetor end. Then, install the sheath on the throttle pedal firewall support plate over a couple different sized washers, you will also need a washer on the other side as well. If you find too many threads are showing on the inside-end, add more washers on the firewall side. Hook the other end of the sheath up to your Lokar throttle/kick down bracket at carb end (only if it's the right length). If you need to shorten the sheath, a thin grinder disc on an angle grinder works great. Just make sure you scoot the solid piece at the end of the sheath further up so it can be slid back into place after the cut. Then, reinstall your throttle cable starting at the gas pedal end. I'd recommend removing the weird looking end adapter of the throttle cable since it's kinda redundant to have that there if the stock gas pedal rod can hold the ball end of the cable in place no problem (like I did, works either way..), put the black securing plug back in, then hook up your ball hitch nut at the top hole of the carburetor's throttle lever right next to the big hole where/if you'd have front throttle return springs.
You'll more than likely notice how much excessive Lokar throttle cable you have, so you'll need to cut it down with dikes. What I do is, pop the kickdown cable off of the carburetor for a bit. Then, for your Lokar throttle cable setup, take the pivot piece & adjuster off the throttle cable, adjust the adjuster so that it is almost at full length, but have it screwed in at least 5-6 threads. Then, pull your throttle cable all the way out till you hear/fell that the gas pedal is all the way up inside. As you are pulling the cable, move the cable towards your pivot ball hitch that is attached to the throttle of the carburetor (make sure the choke/high idle cam is not set at this point/the throttle blades are closed for normal idle). As you match the center of the ball to the cable up, mark the cable 1-2" longer with a sharpie. Next, take the pieces you slid off the cable and slide them back on. But, make sure to have the part that attaches to the carburetor now removed, so that the cable can slide on through the pieces. Double check your cable length once more with it pulled out to be sure you have everything marked where you need it. Cut the cable at the mark you made. Then, screw the adjuster piece (that pop's onto the pivot) back onto the cable, and start adjusting the cable length & adjuster threads to where you have just a little bit of tension at idle on the cable. Secure the cable's adjuster hex nut very good with the allen wrench provided in the kit. Have someone check that you are at Wide Open Throttle with the pedal to the floor (or just about) by having them try to push the throttle open as you are depressing the gas pedal. Make any adjustments as necessary. No adjustments should happen at the cable sheaths that attach to the Lokar throttle/kickdown bracket, unless you find that you need to allow the cable to move-about more freely. Now, you should have enough cable length and adjustability at the threads of the adjuster to get you back on the road!
Older style throttle return bracket
For a throttle return bracket on this first magnum swap, I went and bought an aftermarket piece from the auto parts store and got my throttle return springs installed there. It is bolted on the drivers side front runner of the intake manifold. Use this method if you aren't using Lokar cables.
Carburetor Spacers
I wanted to use a 1" carburetor spacer on the AirGap intake to perhaps get a little more low end torque, but it makes the carb sit way too high, and would need a hood scoop.. So I am running without a spacer, got about a 1" gap from the air cleaner to hood as is.
Update, a 1/2" phenolic resin carb base spacer with a 1/2" air cleaner spacer works great with a drop-base air cleaner in an early A-body.
Oil Filter Adapter BOLT Pictures
Priming The Oil Pump
This probably should've been one of the first things to mention... It's a good idea to prime your oil pump/engine. In order to do this, you must first buy a OIL PUMP PRIMING SHAFT (Part # for the shaft -- P4286800). You'll also want a drill to attach the priming shaft to, have it set to go clockwise. Now before you pull the distributor, take note on where the rotor is pointing at, because when you remove the drive shaft gear that the distributor flat blade shaft rides on inside, you'll only have 6 ways to get that gear drive shaft pointing the rotor in the correct direction 'hex shaft'. You will want the rotor to be pointing at the same spot as it was before when the drive shaft gear is put back in. Ok, so remove the distributor, get some fish line, wrap it around the drive shaft gear down inside, as you are pulling you might need to get a flat blade screw driver on the drive shaft gear, rotate it clockwise to let it raise a bit, to help it come out. Once you've pulled the drive shaft gear out, you'll notice how the shaft from the drive shaft gear has 6 sides, this will play a great role, again, in where your rotor is supposed to point correctly.. Insert the drill with the oil priming shaft down on the oil pump, make sure you got clean 10-30W oil in the pan, and then begin running the drill clockwise for about a minute. It is ideal to have someone help move the crank over as you're priming the oil pump so you're not just sending oil up to 1 head, but rather both Remember, doing this will throw your position off of where your rotor should be pointing once the drive shaft gear has been reinstalled due to the fact that the rotating assembly will be in a different position before you started. A solution to this, make sure you're at TDC on cylinder #1 (Driver's front head) with both intake and exhaust valve closed (on the compression stroke), then you'll be able to dial in the drive shaft gear to rotor position correctly, usually with #1 pointing towards the center of the carburetor. Once done priming the oil pump, put the drive shaft gear back in, slide the distributor back in and if you notice that the rotor isn't pointing where it was, you'll have to pull the distributor back out, insert a flat blade, rotate clockwise 1 out of the 6 faces over of the drive shaft gear, put the distributor back in, repeat the process if needed and you'll get it where the rotor was pointing before, if, you chose to not move the crank shaft at all while priming the motor. Or ignore all of this and make and find out where your new position for #1 sits and go from there.
Priming The Oil Pump Part 2.
DON'T use an impact gun when you're priming the oil pump, that's guaranteed to break something, it has to be a drill, and has to be spinning fast enough to actually see oil flowing with the valve covers off. The idea is to get oil flowing through everything important in the motor, bearings, etc. vs spraying the cylinder walls with lubricant and calling it 'good enough'.
The reason why you really should have the drive shaft gear that the distributor rides on back in the factory correct position is because when you undo all your spark plug wires in the future, or perhaps a next owner does, they're gonna go off the relative position of where each spark plug wire goes according to any Mopar ignition timing picture/diagram, so if that gear is off how ever many sides out of 6, you can be spending a lot of time moving spark plug wires over trying to figure out at what point it's gonna run, rather than just simply looking at an ignition timing picture and getting right on the first time.
Remember again, there's only 6 ways the drive shaft gear will go back in because the shaft is hex shaped. Once you got the drive shaft gear back in, make sure it's where it needs to be like the factory had it, you can turn 1/6 faces over as many times as you want with the gear STILL INSTALLED, just rotate it clockwise with a flat blade screw driver.
Exhaust port difference LA vs MAGNUM
There's a slight difference in the center 2 exhaust ports on Magnums in comparison to the LA's. They're spaced out farther compared to the LA heads and this could pose a performance problem if you use LA headers/manifolds, as well as sealing. The performance on my first Magnum swap in the Valiant is however going really well with stock LA 273 exhaust manifolds. Don't forget to grind the drivers side head for header/manifold clearance, to make it sit flush. Some say you can actually make the Magnum exhaust manifolds work, I've tried this on my early A bodies only to find they run into the firewall, so unless the firewall is modified to recess an exhaust pipe, don't believe they will work on early A bodies, have seen them working on later A bodies, but a rare sight to see stock magnum manifolds in cars. Also, if you are going to use stock exhaust manifolds, you DON'T have to swap the thread studs from LA to Magnum, you can make the Magnum studs work perfectly fine with combining the exhaust bolts/nuts from the Magnum and the LA motor..
10/30/2024 -- Update: You actually can make magnum exhaust manifolds work in an early A body, but it's tight. On another '65 Barracuda I swapped the passenger side over to a magnum exhaust manifold, it is very close to the firewall. Thankfully I had a section of the exhaust still bolted to the magnum manifold from the truck it came out of, and I was able to angle it just right to weld it up to a section of the factory 273 single exhaust. I cut the center cross over of the original 273 single exhaust to make both banks a true-dual exhaust setup, and just welded a flat section of metal over on the driver's side where the exhaust used to come to a Y. It made a MASSIVE difference in performance!! Can only imagine how much more there is to gain by doing the driver's side too! There is another thread on here that talks about converting to magnum exhaust manifolds. For the driver's side, it's a little more tricky. You have to shim the driver's motor mount up with some thick large washers, then convert the manual steering pot coupler to a U-joint style coupler. You also have to cut the steering column back a few inches closer to the firewall as well. You may also have to grind a little bit of the casting away on the exhaust manifold. It will fit, but it will be extremely close to the steering rod. I will be doing the driver's side conversion soon and update how it all works out.
LA vs MAGNUM Timing Cover
Here's a picture of the Magnum timing cover on the left and an LA 360 timing cover on the right. I remember some stipulation on the front main crank seal when I was working on converting my 2nd 318 Magnum to a V belt style. Seemed like some LA 273, even LA 318 timing covers I got my hands on they would have a cast recessed in the timing cover for the seal to sit against, but on the LA 360 timing cover there's no recess, just is a push through seal, same exact seal as on the Magnum.
LA 360 timing cover from an 1986 motor, old seal out (blue) - Now on my 2nd 318 Magnum.
Picture of a timing cover I bought to replace the corroded timing cover on the LA 273 in my 2nd '65 Barracuda (Before the 2nd Magnum Swap), note how there's a cast lip on the front, the seal for this timing cover is smaller in circumference and is installed on the back side. The ignition timing spots are still on same drivers side. But, from what I know on '65 - 273 timing covers the ignition timing spot is on the passenger side, with a section that bolts to the timing cover + has the same action going on with the cast lip.
Broken Dipstick Tube? EZ OUT!
Another thing that typically happens is dipstick tubes can easily break on Magnum engines, the best way to get them out is to use an EZ out bit! Turning the bit counter clockwise grabs into the piece you are trying to remove. While using vice grips and a hammer as you are going counter clockwise, it'll eventually get a bite in the broken tube, keep going till you can't twist the bit anymore, but not so far that it causes the tube to expand and hold-up on removal. Once I got a bite on the broken tube with the EZ out, the oil pan was already off so I took a flat blade screw driver, then slid it down the cast tube part of the block till it touched the EZ out tip. I continued to smack the tip of the EZ out with a mallet & screw driver, out the broken tube came! When I bought a new chrome dipstick, I had to do some very slight grinding on the bottom end of the tube that goes into the block, so it would slide fairly easily in with some resistance into the block, along using a gob of high temp RTV/gasket maker to ensure it won't leak. You have to make sure you bottom out the tube against the tube ring to the block, to ensure that you are getting an accurate reading on your dipstick.
Using LA Exhaust Manifolds
If you choose to use LA exhaust manifolds like I did, you MUST get the heater cross over valve on the passenger exhaust manifold taken out, they typically stick in inconvenient positions and CAN cause burnt exhaust valves, very bad for performance.. Once you've got the heater cross over valve removed, you'll have 2 small holes that'll need to be plugged, simply just weld them up, and make sure you have a very clean surface when doing this. Take it to a machine shop if you don't have the equipment needed to remove the heater cross over valve. I used a sawzall with a fine metal cutting blade, and then trimmed the existing rod/ends down so they were flush inside the port. The ends shouldn't move if your cross over was hard to turn, but if they pop out, weld em in place as plugs. You can use Magnum exhaust manifold gaskets no problem, same for LA gaskets.
Stock Magnum Heads & Performance Heads
The majority of cast-iron Magnum cylinder heads are subject to cracking at the valve seats over time. Most magnums I've worked with have shown small cracks between the valves, this is common. Usually, the cracks aren't severe enough to cause a significant loss in power/compression, but some can. You cannot fully tell how far the cracks go back until you have the valves removed. These cracks can be repaired, but at an expense.. Usually, it's better to source new ones, which leads us to this next! Aftermarket manufactures engineer and produce so many different heads out there. One brand in particular that sticks out for the small block magnums are 'Engine Quest' heads. They are a better designed & flowing cylinder head with added material in areas needed to reduce any chance of cracking. These are specifically made to replace Magnum heads. There's an article out there either on the HotRod network or Mopar Muscle that talks about how to make an easy 400 HP out of a 5.9/360 Magnum with Engine Quest heads. They are sold with the 1.920 intake valve or 2.02 (1.620 exhaust). Check into hughes engines website for these cylinder heads. As far as I've researched, hughes is the only place that installs bronze valve guides in these heads to help prevent sticky valves (something you absolutely do not want to have happen..). You can order them in either intake bolt patterns - LA or Magnum.
Hughes Engines.
Hughes engines is a great place for Magnum performance parts, they KNOW their stuff! Don't let this head cracking portion change your mind about doing a Magnum swap, even if there are cracks, usually, they are minor/more or less hardly affect performance - based off of my experience.
Oil Filter #'s
I usually always buy Wix oil filters, for the shorty filter it's the 51085 - Use this if you aren't using an oil filter angle adapter. For the longer Wix filter which filters more oil (better), go with 51515. Use the longer filter anytime you can, but know that it may not fit depending on exhaust location.
Utilizing The Stock Fuel Injection
I don't have very much info on how to make the stock fuel injection work as all the swaps I've done have been carbureted. I would suggest searching on FABO for more info. There are also quite a few facebook groups about Magnum EFI swaps, and very knowledgeable people in them. I found some useful video/info content on YouTube, check out this guy's channel (MontanaLowGear), he goes through how to Magnum Swap into a Jeep TJ and using the stock fuel injection, very detailed & specific on how to wire everything up correctly!
MontanaLowGear
Removing A Drive Train As A Unit Via Engine Lift
1st - I'd start off getting a 2 ton engine lift, either borrow one or buy one, got a 2 ton lift off eBay. I'd also recommend getting one with extendable legs for better leverage, or at least have a friend stand on the back of the engine lift as the motor is coming out (car batteries work too).
2nd - If your intake manifold is a 4bbl, you can remove the carburetor, buy a lift plate for around $20 at the auto parts store, and bolt it on in place of the carburetor. Yes, those little carburetor studs can actually take the load of hundreds of pounds.. Make sure you have thick washers on before nuts, I used left over Magnum/LA exhaust manifold washers. If you have a 2bbl carb intake on your V8 instead, buy a chain to bolt to the motor going from corner to corner on the face of the cylinder heads. If a slant six, bolt the chain onto the front face of the head and on the top bolt hole that usually secures a vacuum amplifier in place. I bolt mine there to achieve the desired angle for pulling a slant six drivetrain out with the transmission attached. However, there are 2 factory lift bolt holes on top of the cylinder head next to the intake/exhaust manifold.
3rd - Once you have an engine lift setup + lift plate or chain acquired, proceed to drain the radiator by opening the petcock on the bottom of the radiator. Once drained, remove the top and lower radiator hose. Remove your transmission cooler lines from the radiator. Remove the radiator. Remove the throttle cable & kickdown setup if needed. Remove fuel lines going to the fuel pump. Remove any wires going to the alternator & temperature sensor + oil dummy light/pressure sensor. Unhook the battery. If you have power steering, remove the power steering hoses and pump from the motor. Remove the belt driven cooling fan from the water pump. Optional, remove the alternator. Unbolt exhaust pipe(s) from exhaust manifold(s), use PB blaster if you need to get rusty bolts to come off. Remove the shift rod or shift cables going to the transmission. Remove the connector for the safety neutral switch/reverse light switch. Remove the starter from the bell housing (You can let the starter just rest on the center link if you don't want to completely remove it). If your driveshaft is the normal slip yoke type ('66-up cars) make sure you have a oil drain pan ready to catch transmission fluid. I usually get by leaving the transmission cooler lines hooked up to the trans as I pull it out, sometimes it can get caught on the front core support and be a little problematic to get out. You can remove the trans cooler lines from the trans before pulling if you want to. Remove the 1 bell housing bolt on the transmission that holds the transmission dipstick tube in. Pull the dipstick tube. Sometimes, there's another small bolt holding the dipstick tube to the transmission right at where the tube goes into the trans, remove that to remove the tube.. Remove the oil filter angle adapter if you have one, and remove the oil filter. For V8 cars, remove the drivers side exhaust manifold from the cylinder head and let it hang there on the gear box as you pull the drivetrain out. The LA drivers exhaust manifold usually hugs around the steering gear box. Remove the transmission cross member. Undo motor mount securing bolts.
Lastly, get the lift plate or chain or engine leveler (for changing the angle of the drive train when coming out, easiest method) bolted on. You can remove your drivetrain without removing the hood, get creative.. Then, get the lift attached to the lift plate. I like to have the hoist's hook length slack shortened up as much as possible for the max lift. If using a chain, make the chain have as less slack as possible, then use a couple bolts at the hook so the chain won't slide, and then start lifting it up as you push the car backwards. You might hang up at the firewall lip to transmission tunnel, so have someone stand on the trans to get past the firewall lip, and to help achieve the angle needed for getting it past the front core support. Wrapping a tow strap around the tail shaft helps by pulling from under the K frame/center steering link to obtain a better angle. You can also always use an engine leveler instead as bolts in 4 corner intake bolts on a V8 or front and back faces of the heads, easier for changing angles with a simple crank handle. Swoop, right on out! The pic below is from pulling the 273 drive train out of my 2nd '65 Barracuda while using a chain, and friend as counter weight since my 2 ton didn't come with extendable legs, just vertical ones...
Setting an Edelbrock carburetor up
If you are using a 4BBL Edelbrock carburetor (carter/weber), this is a quick guideline for setting up your carburetor to run smoothly. These carburetors are also very easy to rebuild, in comparison with most holleys/other carburetors out there. Have your smartphone handy to take pictures. With the carburetor off of the engine, you should check your float levels as this is the #1 important thing towards calibrating your carburetor. Remove the 2-3 small cotter pins securing the rods to your accelerator pump, choke, and high idle. Remove the accelerator pump screw and remove the parts. Loosen the screws securing the top doors to the metering rods, rotate the doors so that the rods pop up, remove the rods + springs. Remove all top securing bolts and separate the top half from the bottom of the carburetor. To check your float level adjustments, take a small ruler or measuring tape and measure how far the floats drop. You want about 15/16" to 1" of a drop. To adjust the float drop, remove the pin that holds the float in place, remove the float, take some pliers and gently bend the small tab the direction needed to raise or lower the float drop setting. You will need to reinsert the float with the pin and check your measurement several times till it is correct. Once that is dialed in, move onto setting the float rise.
To set your float rise, now flip the top upside down so that the floats are not hanging. Grab a 7/16" drill bit, then slide it between the gasket and the float. To adjust the float rise, carefully bend at the point where the float is soldered to the adjuster tab, while making sure you do not bend the smaller tab. Once the drill bit barely touches the tip edge of the float, you are set. Double check the float drop once again in case you need to re-adjust it. To test that your needle & seats are working, try blowing air in the fuel inlet with the top still upside down. If you cannot hear or get air to blow by, the needles are seated properly and working. You may need to clean the needles a little with mineral spirits or with a little bit of carb/brake cleaner on a lint-free rag. Double check that there isn't any junk in the lower body of the carburetor, but while you are there, just blast everything out with some brake cleaner and an air hose.. Put everything back together.
I like to insert the metering rods & secure the doors before snugging all the bolts down to the top of the carburetor. Next up is adjusting your idle mixture screws. Turn both of your idle mixture screws all the way in, but do not go tight with them as this can cause damage to the body. Then, back both screws out about 2 full turns, while counting each half turn of the screw. This should be a good baseline for setting the mixture screws to where you can further fine tune them later with the engine running at operating temperature. Adjust your idle screw to where the throttle blades barely expose the transfer slots. Make any necessary adjustments to the high idle cam as needed. Make sure the port on the back of the carburetor is plugged with an NPT fitting/plug, unless you are using it for a brake booster. Up front, the left smaller port will be used for your vacuum advance timing. The right smaller port that sits lower is for ignition timing that goes off of the manifold, plug this port. The large center port will be used for a PCV valve, if you don't want to use a PCV (not recommended -- unless you have a breather or two..) it can be capped. Hook everything up, including the fuel line.. Fire the engine up, let it get to operating temperature, and make any adjustments needed to the idle mixture screws/high idle cam/idle.
You may need to further tune your carburetor with different sized jets & metering rods, only do this once you have your ignition timing dialed in. The colored spring that goes over the metering rods are more for cruising/part throttle driving. There are 5 total different rated springs, with orange being your baseline average spring. You can visibly watch the metering rods pull off the jets with the engine running. Just loosen the metering rod door screws, move them half way out to partially reveal the metering rods, tighten the screw and fire the engine up. With a few quick revs you should see the metering rods pop up for a split second. While experimenting with these springs, you will be able to tell if you need a lighter or stiffer spring.. Only make changes to your metering rod sizes first while tuning, before changing your primary jets. Keep notes on what combination you find that works best with your application.
Ignition Timing
Firing order between an LA and Magnum engine are the SAME. The distributor spins clockwise, and the firing order is 1 8 4 3 6 5 7 2. Make sure you have verified that the rotor of the distributor is pointing at cylinder #1, and that you know that cylinder #1 is at Top Dead Center with both intake/exhaust valves closed. It's ideal to have a tachometer hooked up at this point if you aren't experienced with knowing by ear with where your rpm's are roughly at. Have your distributor clamp snug, but loose enough that you can still rotate the distributor to make adjustments. Next, with the vacuum advance port plugged off at your carburetor, fire the engine up. Your timing at idle (650rpms) should be anywhere between 10°-14° degrees before top dead center (BTDC = Advanced -- Don't confuse Advance & Retarded ignition terms..). Use a timing light while shinning it on the harmonic balancer as the engine is running, to see where your timing is at based at the 10-0-10 mark on the timing cover. The top section of the 10-0-10 will be BTDC, 0 will be TDC, and the below section will be ATDC (After Top Dead Center - Retarded). Advancing the ignition timing is turning the distributor counter-clockwise, and turning the distributor clockwise Retards the timing.
Begin rotating the distributor clockwise or counter clockwise till you're around 10 degrees BTDC according to the flashes of the timing gun, while looking at the timing slash/mark against the timing degree # mark on the timing cover. After getting the idle timing in the ball park, I'll let the engine get to operating temperature, then check it's total timing. To check total timing, rev the motor up around 3000+rpms for short periods of time, and set your total 'Advance' timing somewhere between 32°-36°. If the vacuum advance on the distributor is hooked up, you will have a false reading because the timing will be advancing further, this is why you disable the vacuum advance during this procedure. It's common on a first start-up to be 180° out on the distributor, which will cause it to backfire/not run. It'll let you know that you have to check your firing order, and/or pull the distributor out to rotate the flat blade shaft of the distributor 180°. You can move your spark plug wires around so that they've all moved in a 180 degree circle as well, if they're long enough..
I used to often buy the sun pro super tach 2/II from eBay around $30-$40 and they work pretty good if new, and make sure on the back of the tachometer too that out of the 3 switches 4/6/8 you're on 8 cause it calculates rpms different based on how many cylinders there are. Autometer will have much more calibrated accurate tachometers.
Power Steering Pump LA - Places To Grind For Fit
On my 2nd Magnum Swap, since I went to a V belt setup, I wanted to mount my power steering pump and found that I couldn't make my alternator or power steering work with the newer water pump. I ordered a '86 Dodge ram water pump for a LA 360 to work on my Magnum, but the snout extends too far.. So, I swapped a good LA 273 water pump on my Magnum, while finding out you actually have to have this type of 273 water pump if you want to bolt up your existing 273/early A body V belt accessories. The alternator & alternator bracket bolted up with NO problems at all. Take note on how the newer/later LA water pump's bypass and heater hose fitting are part of the pump instead of removable, like on the early style water pump. While mounting the LA 273 power steering pump, I found out I had to do a little bit clearancing on the driver's cylinder head to make it fit. See pics below..
Below 2 pics show the later water pump that will NOT work with 273 LA accessories.
Harmonic Balancer/Vibration Dampener For LA V Belt Conversion
For a harmonic balancer/vibration dampener for my 2nd 318 Magnum (internally balanced) I went with the SUM-163273 balancer from Summit Racing. I used an air driven impact gun to pull the front crank bolt out which bolts the harmonic balancer on. Then I used my harmonic balancer puller (can rent one from auto parts store) to remove it. On most of these Magnums the serpentine pulley and harmonic balancer are one, 'non separable'. Thus the reason for sourcing a new harmonic balancer with no pulley attached. Next, I oiled up the front timing cover seal, and shaft on the new harmonic balancer. Partially slid it right on the snout of the crank, then used a 2x4 and mallet to give it a good wack/start onto the snout. You can't go wrong putting this pulley on because it's only keyed 1 way. Once in place, I drove it home with the large crank bolt and impact gun (Don't go too crazy). There's actually a torque spec for getting the crank bolt tight properly, but I just kept going till I can't see the dampener moving on anymore, closing the gap between the timing cover. It had like less than an 1/8" from the back of the dampener to the timing cover. I was going to use my '80's truck LA 360 V belt crank pulley that have 4 V belt grooves, but found out it wouldn't work with my upper 273 pulleys because the circumference of 2 of the pulleys are bigger and rub against the upper 273 water pump attachable pulley. You have to understand that there were many different configurations throughout the years in Chrysler's line up of vehicles, different sized pulleys, different length/spacing, etc. So I had to go with my 273 crank pulley that has 2 V belt grooves (one for driving the alternator/water pump, the other for driving the power steering pump). The LA 273 crank pulley only lets you bolt 5 out of the 6 bolts used onto the dampener, which is fine.. But at the time I wanted to have all 6/6 bolted up with the LA 360 crank pulley, just wouldn't work out.
Installing External Electric Fuel Pump
I went with a low psi Holley external electric fuel pump due to no mechanical fuel pump eccentric on the Magnums. If you use one of these electric fuel pumps, you CAN NOT install the pump in the engine bay because it will burn the pump up, it's a pusher, not a puller. I've had a cheaper electric fuel pump before this one, it acted up when installed up in the engine bay. It would over heat, not from the engine heat, but because it's too much for the pump to pull the fuel from the tank from such a long distance and pump it to the carburetor. So I bought this holley low psi electric fuel pump, thinking the cheap fuel pump was bad, but the holley did the same thing when installed up in the engine bay, it would over heat, quit pumping, till it cooled off and begin to kinda pump again till it overheated.. I found out that you HAVE to install an electric fuel pump 10 vertical inches away from the fuel tank. It is much better to have a return line back to the tank so that the fuel pump can stay significantly cooler. They sell fuel filters that have a 1/4" port to attach a return line to, but keep in mind, this may affect the fuel pressure going to your carburetor, depending on how much psi the electric fuel pump is putting out. I installed an electric fuel pump on the frame rail and tied it into the factory 5/16" fuel line. I eye balled and cut a certain amount of the metal fuel line in order to install the fuel pump. I installed the screw-in filter that comes with the pump, and then installed the pump at an angle.. It followed the down/up slope line of the fuel line & frame rail, and it is positioned relatively below the fuel tank so that there should always be some-what gravity fed gas behind the pump.
As I had the pump positioned where I wanted it, I grabbed a small flat blade, then etched in the center of the mounting holes onto the frame rail so I'd know right where to drill. The fuel pump comes with self tapping bolts. Once the 2 holes were drilled out of the frame rail, and slightly big enough to accommodate the self-tapper bolts, I used an angle impact to install the bolts. You can easily ruin the threads of the self-tapping bolts if you don't first drill some holes into the frame rail. The bolts tapped some very short length threads into the drilled holes in the frame rail. Afterwards, I eventually bolted the fuel pump in place, while using the black/negative wire of the fuel pump over one of the bolts to ground to the body. Note, the bolt closest to the top will probably be nearly impossible to completely tighten down with the amount of space given, just at least have the lower one installed, and tight (with a lock-washer preferably). I then installed some fuel hoses on the fuel pump, to the factory metal fuel lines. Because after cutting an X amount of inches out of the factory fuel line, and without a flare, I will use at least 2 hose clamps on the end where the rubber hose clamps onto the fuel line to mitigate any chance of leaks. On my 2nd magnum swapped mopar, for the positive wire of the fuel pump I was pretty meticulous on how that routing went from the back towards the interior, then to a switch. On the first magnum swapped Mopar ('65 Valiant), There's a few rubber grommets that go to the trunk. So I slit a small hole in the center of one, ran a long wire from my aftermarket switch, to an inline fuse, then all the way back, through that grommet and then to the fuel pump. However in my '65 Barracuda with the 2nd Magnum swap, I used a ton of zip ties by zip tie-ing a very long wire going from the aftermarket switch inside, out the firewall, all along the brake line that goes to the rear axle and then spliced it in with the fuel pump. The fuse I used was a 10 amp fuse (ATM/ATC fuse). Only run the fuel pump with fuel, if you run it dry, it wears them out quickly because there is no gas to lubricate the parts inside that do the do..
The holley electric fuel pump in this '65 Valiant that was installed in 2015, is still going strong to this day (11/11/2024). Another cheaper brand I've used in my blue '65 Barracuda lasted only 4 years.. If it sat for an extended period of time I would have to pressurise the fuel tank with air, to force the fuel through the lines & make it prime the pump again to get it working, up until the day the fuel pump completely stopped pumping at a panda drive thru... There's a reason why electric fuel pumps are installed in the gas tank.
Oil Pressure Gauge
It's HIGHLY recommended that you have an oil pressure gauge for any running engine. It's a BAD idea to rely only on the oil pressure dummy light on the dash/instrument cluster panel, because what happens when the light bulb there burns out and you have a real oil crisis going on? Boom..
I went on eBay and bought a cheap, good working electric 2" oil pressure gauge with a sensor/sending unit that screws into the block right by the distributor. The sending unit screws right in place of your dummy light switch, and you simply just wire the gauge to the oil pressure sending unit. You also need 12V to the gauge when ignition is on, so it works.. It's ideal to have 60psi oil pressure (cold). It is NORMAL for the oil pressure to come down as the motor heats up, normal should read around 30-40psi. You want about 10psi of oil pressure per 1,000 rpms. Some of these electric gauges may wig-out with electrical draws from other accessories in the wiring system, so they aren't always completely accurate. However, they are much better than nothing!!
Voltage Meter Gauge
It isn't a bad idea to get a 12 volt meter gauge, so you can see where your battery voltage is while the alternator is charging. 14.7 charging volts considerably is normal. If the system's overcharging, you're at risk for frying electrical components over time, and chancing having your battery literally explode. Out of all the classic Mopars I've owned over the years, every single one in it's life had some unfortunate event of a battery exploding, based off of the battery acid marks that are etched into the bottom of the hood, inner apron/inner fender and front core support, etc. So... make sure you got a Mopar specific voltage regulator, or at least one that charges correctly, and that the body of the voltage regulator is grounded. Make sure that you have a nice thick gauge wire going from the alternator, then straight to battery, and keep an eye on your voltage every now and again. Don't forget to bypass your factory amp-meter/ammeter to prevent future fires from behind the instrument cluster panel/dash.
Water Temperature Gauge
If your water temperature gauge isn't reading correctly on the instrument cluster panel (most don't) then it's also HIGHLY recommended that you get an aftermarket gauge so you know where your engine temperatures are at. The last thing you want is to be overheating and not knowing before hand. These gauges can be found on eBay/amazon as well.
Aftermarket Fuse Box
You can get aftermarket updated ATC/ATM fuse boxes from eBay/Amazon for dirt cheap. I've used them on some builds where the factory fuse block absolutely needed to be replaced due to excessive corrosion. The updated fuse block can be bought with an x-amount of circuits available, typically 6 is what you need. There is a main positive connection on the block to tie your main 12V 'hot' wire from the existing fuse block to, and on the edges of the new fuse block is where you can secure your circuits to. But note, during this conversion you need to pay attention to how the factory fuse block is wired up. At least 3 circuits get power when the ignition is turned to 'on', while the other 2 are constant hot. There is 1 circuit that is left, which is either constant hot or keyed power as well. The circuits that got power from the ignition switch, I used in-line ATC-ATM fuses. Hook your stuff up however you'd like, but please, make it easy for the next owner to understand..
MOTOR MOUNTS
Magnum 318 and 360's are NOT the same on the drivers side... You more than likely will run into this problem '67-'72 swaps. The 318 Magnum has 4 holes on the drivers side while the 360 Magnum has 3 holes, plus, the 360 Magnum's drivers side is the same narrower width just like the LA 360, the Magnum & LA 318's are wider. For '67-'72 cars you CAN still use your passenger side motor mount no problem, same for pre (before) '67 cars if you use a long high grade bolt on the lower 1 hole. The way to correct this for you guys who are 5.9L Magnum Swapping into a '67-'72 car is to buy a set or just the driver's side motor mount for a 5.9L Magnum on Schumacher Creative Services website, or, you may still be able to make the drivers side from your previous LA V8 to work with an extra nut or stack of washers to shim up the distance between the ear of the block to the motor mount. 318 Magnum's drivers side WILL work with early/later LA 273/318 motor mounts. Again, for the 5.9L/360 Magnum & 5.2L/318 Magnum, early/later 273/318 LA mounts WILL work on the passenger side. For pre '67 cars you CAN use your LA 273 drivers motor mount without issue, again, for the passenger side just use a long, high grade/heavy duty bolt to tie in the motor mount to ear perch. Remember, LA 360's & Magnum 360's motor mount ear perches are different in dimensions/closer inward compared to the 318's. If you're expecting your stock LA 360 motor mounts to work on a 318/360 Magnum, they will more than likely not work on the LA/Magnum 318, but should bolt up no problem to the Magnum 360.
I'll probably think of more stuff to write about, refresh this page every now and again to see what's been added or revised! There's so much info here, use CTRL + F on your keyboard to search for specific things, again.
Automatic Transmission Seals & Tips
10-14-2024 -- A side note, rebuilding the TorqueFlite Chrysler 904/727's can be done by yourself. Refer to 'Tom Hand's' book from Amazon:
Chrysler TorqueFlite A-904 and A-727 Transmissions: How to Rebuild (Workbench How-to)
This book is incredibly detailed, with many pictures, troubleshooting and guidance.You will be amazed how relatively easy it is to rebuild one of these units, and save yourself a ton of money down the road, along with a new skill learned!!
A&A Transmissions & Andrews Racing Transmissions is usually where I source my transmission parts from.
I've rebuilt 7x 904 transmissions so far over the last year, and wish I knew years ago what I know now.. Now, getting back to the basics:
Before throwing your 904/727 back in or bolting it back up, it's a really good idea to replace a few seals and potentially bushings. The most important, be sure you replace your front pump seal that the torque converter snout slides & spins against. First, check to see how worn the snout of your torque converter is, if there is a perceivable lip, or even cracks (this is common), it is recommended to have the torque converter rebuilt or replaced. Speedy sleeves are sold to remedy the lip problem, but you will need a larger inner diameter bushing for the front pump by then to make it work. Your local 'TranStar Industries' can take your old torque converter, and ship it off to be completely rebuilt for around $100, as well as have your stall speed altered (to an extent) depending on your application. Ideally, you should replace the bushing in the front pump as well. As this bushing gets worn, it too, can cause a leak, the front pump seal works to an extent on sealing in so much fluid. To keep things relatively simple in this article I may/may not add a more detailed section of going in depth with rebuilding a torqueflite, so with that put to the side.. Assuming your front pump bushing is still good, and torque converter snout is good, we can move forward with replacing the front pump seal. Grab a seal puller from your local hardware/autoparts store as it comes in handy. Carefully hook into the old seal enough to get behind the metal section of the seal, and pry gently. You may have to alternate positions to work it out, be careful not to gack the bushing sitting a little further behind the front pump seal. Once removed, grab your new seal, some manuals will suggest to use a little RTV around the metal ring of the seal during installation.. I just use ATF to help it slide in and let the paint coating do it's job to seal. Make sure the circular spring behind the lip of the seal is nicely in place. Find a correct sized large socket that's able to allow the input shaft to go through the center, or get creative, stack a couple rolls of electrical tape up on top of a large socket, and hammer the seal home carefully into the front pump. Do not compromise the metal ring of the seal, if it distorts the rubber, this can cause a leak.
Before seating the torque converter in the front pump, make sure the snout or at least the lip of the seal is lubed up with transmission fluid, or even better, a little bit of white lithium grease. You can install the torque converter in the front pump by either standing the transmission up, or in it's normal position. There will be 3 initial drops before it's fully seated, and if the mounting tabs on the torque converter to the flex plate are sticking out past the bell housing, that means it's NOT seated. If you over force the matter, it's not hard to get to a point where you can physically break the ear tabs off of the pump gear inside of the front pump. While trying to seat the torque converter, you may have to slightly pull the torque converter outward and rotate it to different positions till it finds it's happy spot/lined up with the front pump gear tabs. I'll usually look inside with a light to see exactly where the ear tabs of the pump are lined up, and then insert the torque converter as such. If I have the transmission sitting in it's normal position, jiggling while rotating the torque converter usually gets it in after some finagle and finesse.. Do not despair, you will figure it out.. Be sure to replace your shift shaft seal, as well as the rubber inner seal that rides against the kickdown lever rod to the valve body, as those are a very common source of leaks. The way I replace mine is by dropping the valve body. If your valve body hangs up during removal, get your drive shaft in the tail shaft (or a spare yoke), slightly turn it, and it will release the parking lock rod. Pop the old shift shaft seal out from underneath with a flat blade screw driver, then lube the new seal with transmission fluid. Pop it in from above using the correct sized socket and a hammer. Do not compromise/bend the metal on the seal during installation. To replace the little rubber kickdown rod seal, remove the c-clip & washer, but leave the rod in place. Take a prick tool and dig out the old seal, then grab your new seal and install it. It will look wrong/upside down because it'll have a groove in the seal, but this is the correct way it is installed. Another very common leak is at the pin that slides through the Low/reverse band apply anchor. Sometimes if you clean the outside area up very good, you can gob some RTV/gasket maker on the end of the pin, and it will stop the leak. The proper solution is to pull the pin out and replace the o-ring (some will have 2 groves that take 2x o-rings), but this means you have to remove the tail shaft housing, plus the pan of the transmission to gain access to the pin.
Check to see how much slop there is back n' forth with the yoke of your driveshaft inserted in the tailshaft, keeping in mind that your u-joints could be worn out as well (replace them if needed). If it's excessive (this is usually uncommon) while moving the yoke up/down while inserted into the tailshaft, then the bushing that the yoke rides against in the tailshaft needs to be replaced. Bushings can be sourced from A&A Transmission, Rockauto, and other places. To replace the bushing, stand the transmission up with the bell housing on the ground. Take a flat blade screw driver and tap around on the ring edge of the outer metal part of the tail shaft seal to work it out. Remove the speedometer gear. Remove all 6 tailshaft housing bolts, remove the 2 large philips screws securing a cover, use large snap ring pliers to open up the snap ring, and then pull the housing off. You may need to gently persuade it off with a mallet. Rent a bushing driver set from your local autoparts store, find the correct sized bushing driver, remember how/where the old bushing is positioned inside, and drive the old bushing out. Grab your new bushing, test fit it first on your yoke before installation, I have found 2 very slightly different sized inner diameter bushings before (we're talking thousands of an inch difference -- ATP vs Pioneer brands), if it's too snug or won't slide on, try taking some emery cloth to the new bushing, or source a different one from another brand.. Lube the outer portion of the correct sized tail shaft bushing up with blue loc-tite, then drive it home in the same position the last bushing was installed so the oil feed hole is in the correct spot (using a larger bushing driver). Reinstall the tailshaft with a new gasket that is lubed up with a light layer of grease. You will have to spread apart the large snap ring again while wiggling the housing back on. If it's still a struggle reinstalling the tailshaft, here's what I would suggest. With the old tail shaft seal removed, take a rag with a pair of vice grips and attach it to the tailshaft, then slightly pull upwards to allow the snap ring to snap back onto the support bearing. Next, dab a small bit of RTV on the threads of your 6 bolts that bolt the tail shaft up to the transmission. You can use a new cork style gasket on the tail shaft snap ring cover, or, get an updated snap ring cover that uses an o-ring style seal from Andrews Racing Transmission. Go snug on the screws. Take a look at your speedometer gear, it will have a number on it that will correspond with a range for where your speedometer housing is supposed to be clocked in at.
Lastly, replace your tail shaft to drive shaft seal. Lube the inside of the seal up with ATF, and also make sure the circular spring is in place. Take a large socket that fits nicely, and drive the seal home into the tailshaft housing. Next, clean everything up as best as possible, replace the filter on the valve body & pan gasket. Make sure your transmission cooler line adapters are snug so they don't leak, I like to use teflon tape here. If you find that your dip stick tube leaks and no new O ring around will do the job readily, simply get some high temp RTV and gob it around that area of the tube, make sure you got a clean surface on the tube and also in the hole of the trans so it'll adhere better, use brake cleaner to make the surface absolutely clean. It's best to do this when you don't have transmission fluid in the pan, let it setup at least a day before adding fluid, with the tube installed.. This has worked for me in the past, but I would strongly recommend sourcing the correct sized o-ring as it will do the job easily without sealers. Also, DON'T forget to bolt the dipstick tube back up to the bell housing - to the motor. Same goes for the bolt that holds the tube to the trans if you got the older setup there (usually 1969-down).
An awesome tip for getting a firmer 1 - 2 shift out of your 904/727 is to take out the big accumulator spring that goes between the valve body and servo piston. This spring helps soften shifts, which is not quite ideal for the longevity of a transmission as it lets your kickdown/2nd gear band slip slightly more during the 1-2 shift. You actually want firmer shifts, which will create less heat on the friction material at work. By removing this spring, you speed up the process of the kickdown/2nd gear apply servo applying the band - doing this is referred to 'knocking granny's head off', especially with a well setup shift kit. Source a clean 3" long (Has to be about 2.952" long) 3/8" extension and insert it underneath the accumulator piston, so that it blocks the piston in an upwards position/about rests against the valve body. The reason you insert a blocker rod underneath the accumulator piston is to keep the piston from moving/slamming back down into the valve body during a shift. If your application isn't going to be seeing any crazy horse power, then leave the transmission alone, and make sure your kickdown adjustments are absolutely correct. See that yellow spring in the pic below? Throw it in the garbage, or keep it if you use a performance shift kit down the road and don't want a fairly jolting healthy 1-2 shift.
Rear Axles
I'm still using the 7 - 1/4" rear ends with 2.76 gears (highway gears/stock) in both of my Magnum Swapped 318 cars and they're holding up just fine, even with some fun burnouts, but I intend on throwing in an 8 - 1/4" or 8 - 3/4" rear end later on. As long as the 7.25 doesn't get traction or hook during a burnout, the gears inside should last surprisingly quite a while. Inspect everything that holds your rear suspension together, u-joints, bolts, nuts, bushings, etc. It's important to make sure everything is in good shape and torqued to spec. Polyurethane bushings are a must these days, as just about any rubber made suspension parts will NOT last anywhere near as long as how stuff was manufactured years ago.. Do what you can do under your set budget, and don't get too carried away building up a rear axle that is overkill for the application in mind.
Driveshafts
If you can, upgrade your small u-joints to the larger style u-joint, or at least use a spicer non-greasable u-joint as they are stronger. Don't cheap out on u-joints, make sure you measure yours and know exactly what you need, there are slight differences out there that will drive you crazy.. I have not had very good luck with buying u-joints from o'reillys lately.. Most haven't fit like they should. My small block Magnums have a tendency to be harsher on the smaller u-joints and sometimes cause on/off excessive vibration while out on the road. Inspect your u-joint straps to see if the bolts are in good shape. A lot of the time the lock-washers on those small bolts are worn out and need to be replaced to help keep your u-joint strap bolts from backing out over time. Blue loc-tite helps a lot here as well. If you are upgrading to super stock leaf springs, keep in mind this may affect your pinion angle of the pumpkin and cause pre-mature wear on the needle bearings in your u-joints (same goes for excessive burn-outs). The common Mopar u-joints out there are the 7290, 7260, and 1310. There are conversion u-joints available as well, so say if your 8.75 third member/pumpkin's yoke uses the smaller style u-joint, but your driveshaft uses the larger u-joint, this style of conversion u-joint adapts both to work together, and it's reverable! See Dr. Differential's website for more.
Brakes
I'm still using the 9" drums all around on the '65 Valiant with the first Magnum Swap, they work ok, disc brakes are a much better setup obviously so I look forward to converting the fronts later on, my 2nd '65 Barracuda has 10" drums all around which are way better than 9" drums, but also intend to swap the fronts to discs on that car as well.. For early A body disc conversions from what I've researched, you can get the conversion kits from SSBC brakes, or wilwood. They even have disc conversions that'll fit over your stock 9" or 10" spindles. As far as the upper and lower ball joints go, they should come with the conversion kit, if not, You can use '73/'74 types that'll bolt right up, but they typically need the bigger upper & lower ball joints.
11/11/2024 Update -- Why you need to convert to a dual master brake cylinder!!
Early 2024, I got a phone call from my buddy who bought this very same white magnum swapped '65 Valiant back in late 2020. It was a day that I feared, that tragedy struck... Late at night, he got off an exit from I-15, went to hit the brakes to slow down, and immediately found out that the pedal went straight to the floor. He lost all brake line pressure because of a brand new failed wheel cylinder from rock-auto. The main single pot brake master cylinder was still in place (it had been replaced before as well), unfortunately, it was never updated to a dual master cylinder. The original 7.25 rear end to that car got replaced with another 7.25 at some point, and the emergency brake cable wasn't hooked up either.. With the limited amount of time he had to react, he dropped the transmission right into 1st/low and swerved back n' forth to bleed off as much speed as possible, but sadly, the intersection ahead already had a red light. He smacked hard right into an uber that was traveling across the intersection, sending the driver to the hospital from mostly the wind getting knocked out of him. The passengers inside the uber were ok.. My buddy in the Valiant had messed up knees from hitting the dash, at least he was wearing a seat belt at the time. The entire front end of the Valiant was bashed in pretty bad, the frame rails were bent, and none of the doors would open/shut correctly anymore. The insurance totaled the Valiant, and it was the end to a legend. Thankfully, the magnum drivetrain now lives on in a Dodge Coronet of theirs.
There is a reason that in 1967 the government made it mandatory that all car manufactures would have to switch over to a dual master cylinder, so that in the event that there is a brake failure, at least you will have half of them working instead of none at all. If your car still has a single pot master cylinder, please consider upgrading it vs betting it's going to save yours or someone else's life. See on 'The Early Valiant Barracuda Club's' website tech center for converting your ride to a dual master cylinder.
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Mechanical fuel pumps on a Magnum
There's a site suggested on magnumswaps website that sells an eccentric to bolt to your cam shaft if you choose to go V belt style & want a mechanical fuel pump (Scram Speed? Believe Hughes Engines sells one too). On my 2nd Magnum swap I thought about this and did quite a bit of research only to find most people saying the aftermarket made eccentric adapter was engineered poorly or simply doesn't work, but some still saying it works for them. I just got a mechanical fuel pump block off plate from JEGS since my 2nd magnum swap was converted to a V belt style pulley system, and got another low psi Holley electric fuel pump. Electric fuel pumps are very good at keeping a constant supply to the fuel bowls of the carburetor.
HEI all-in-one Distrubutor NOTE for LA V8's:
Something that needs to be noted about the HEI all-in-one distributor, there's 2 different versions in height, usually found on eBay. One has a longer shaft, and the other with a shorter shaft. The short shaft will NOT work with a later LA 2BBL intake manifold because the runners of the intake are designed differently/sit closer towards the distributor, and, the short shaft version will interfere with most bigger oil sending units you install. It's better to get the longer shaft version for clearance, but the longer shaft version may also come in contract with later A-body wiper motors. This was something I noticed as I was fixing to throw my short shaft HEI distributor on my LA 318 in my '74 Duster -- So I guess in all actuality, you shouldn't have this issue on the Magnum AirGap intake manifold with either version, other than just the oil sending unit accessories portion being problematic with the short shaft version.. A tree splitter adapter to screw into the block for an oil sending unit and/or accessories, such as a fuel pump switch, would be an ideal thing to have when using the shorter shaft distributor for clearance.
RECOMMENDED PARTS RECAP
Here's a list showing all the parts I talked about above in this article + some that weren't listed.
- Edelbrock Intake Manifold AirGap 7577
- Oil Pan off Summit Racing - sum-g3536 (Usually out of stock nowadays... See JEGS version, or just get a car style LA-360 oil pan off eBay/wherever)
- Water pump - GATES 43034
- Thermostat - Gates 33509
- Edelbrock 1406 Carburetor (600cfm Electric choke style, 1405 is manual choke)
- Mopar Magnum Valve Covers
- Dorman Air Conditioner Bypass Brackets 34178 (RNB-34178) <- Optional
- Bypass hose - Gates SX6229
- One piece Magnum oil pan seal - DNJ PG1142
- Engine gasket kit (NOT an entire gasket/seal kit) - FELHS9898PT1
- Double Row Timing Chain - TC3028
- Thermostat housing replacement - 902-318
- E3 spark plugs - E3.48 (for Magnums), and E3.46 (for LA's)
- Lokar -- Kickdown cable - Lokar KD-2904HT -- Throttle cable - TC-1000HT -- Lokar SRK-4000 Stainless Steel Throttle Cable Bracket And Springs Kit (Kickdown).
- Chrome oil dipstick - SP7172
- Mid-sump oil pickup tube (See MEL-72-S2 on Summit Racing)
- Wix Oil Filters - Long 51515 - Short 51085
- 904 Transmission's front pump seal - 12070
- 10" LA-273/318 + 318 Magnum (non-weighted/internally balanced) X shaped flex plate - FRA303
- Autometer gauges - I'm making a special mention of this companies gauges for they're highly regarded in quality & accurate functionality, if you want the best gauges, Autometer's where they're at.
- More to come...
NOTES
April 21st, 2017 -- I drove my 2nd 1965 Plymouth Barracuda down to Mopars At The Strip near Las Vegas a couple weeks ago, the 2nd 318 Magnum held up great!! Round trip was over 1,000 miles. I did however have a problem with fuel starvation 3 times on the trip. The Holley electric fuel pump mounted 10 vertical inches away from the fuel tank on the frame rail was heating up and would eventually stop pumping, had to pull over 2 different times to let it cool off and continue on. The next morning I swapped a spare on for the travel back home, it happened again only 70ish miles into the trip back. I figured that if I kept my speed between 60-65mph instead of 70-80mph (70mph is 2,700rpms w/2.76 gears fyi) it would put less demand on the fuel pump, therefore make it run cooler. Thankfully, that was most likely the case since I got back with no more problems. I believed that the sending unit pickup screen is clogged, which would make the electric fuel pump have to work harder to pump gas freely. The car still has the original gas tank, and possibly fuel sending unit, so will be replacing both shortly and am betting it will fix the problem, weird how that never happened going 70-80mph on the way to Saint George Ut where I stayed at a relatives to head to MATS the following morning and back to SG with no problems, just the 2nd run/day to MATS and back. Besides all that, it was a very awesome experience to drive my 2nd Magnum Swapped Mopar to this event, was very fun at MATS this year 2017.
LATER A BODY MAGNUM SWAP -- 1973 PLYMOUTH DUSTER 360 MAGNUM
2/4/2018
I've embarked on my 4th Magnum Swap into my 1973 Plymouth Duster with a 360 Magnum. There's a few things that have been different for me while going through this process and I will be writing up about what's been done so far to it soon.
Update 9/16/2018, I traded the '73 Duster for a '74 Scamp earlier this year and never ended up firing the 360 Magnum up in that car, however, after selling the '74 Scamp recently, I'm funding another 360 Magnum build for my '74 Duster and will post updates + some of the same challenges I went through with the '73 Duster, here.
LATER A BODY MAGNUM SWAP!! 6TH MAGNUM SWAP IN A 1974 PLYMOUTH DUSTER! 10/18/2019
So I've finally got around to Magnum Swapping my 1974 Plymouth Duster I've had sitting around since December of 2016. Pulled the tired LA 318 & 904 over the winter of 2018. There were a few little things that were different going through this process I felt it be worth mentioning here to help you guys out with later A bodies. So, main key points I'll cover is header installation, fuel pump installation, battery relocation, etc.
HEADER INSTALLATION
For this ride I bought Summit Racing ceramic coated headers, not just for looks, but to also provide an advantage for lowering engine heat temperatures significantly, which helps make things under the hood last longer and allows the motor to breath just a bit better. I had Dougs non-coated headers to begin with, they were smashed pretty bad on drivers side more than likely from speed bumps and torsion bars set too low. So with the 3" collector exhaust still there, unbolted from the old headers, I had undone the idler arm from the k member, swiveled it over in line with the center link, and also undone the inner tie rod end next to it in order to slide the driver's header right on in. I only replaced the inner tie rod for now and bolted the idler arm back up, when removing them, a small sledge hammer helps a ton, you can sometimes get lucky just smacking the outer portion of the center link to release the the tie rod, other times you'll have to find different methods for removing them. I like to undo the castle nut, flip it around and thread it on just a little, and smack it. If I'm planning on saving the tie rod end, I won't use a pickle fork as it will destroy the rubber grease boot.
So with the drivers header in, I set the passenger's header in place, and left both there NOT bolted to the exhaust until they were bolted to the engine first. Use a couple bungee straps to keep the headers from sliding down in your way when installing the drivetrain. Leaving the headers completely unbolted during the whole Magnum Swap process helped a TON by getting the starter in, trans lines, etc. Now keep in mind if you have stuff that you think might not be good next/near the headers due to heat, it's recommended you get some heat shielding tape or wrap, would recommend this for the mini starter big time.
Use a couple zip ties to hold the header gasket on, makes it sooo much easier, and make sure the bolt holes are aligned. So once the drivetrain is all bolted in and everything's hooked up to your satisfaction to where it won't be a pain to install anything else as the headers are bolted in, proceed to bolt up the passenger header, as the gratification you'll receive for how easy it was will prepare you mentally, spiritually and physically for what's about to happen on the drivers side. Do use a floor jack down on your headers if needed to help get the bolt holes more aligned to get the bolts started into the head, make sure ALL are started so you have some wiggle room to get the next one in.
You will find it is rather quite a P.I.T.A to get the last 2 header bolts in towards the firewall on the drivers side because all manufactures for "lower priced" headers can't seem to figure out or care how to make your life easier by adding some more clearance or more slight bend recesses next to the header tubes in order to get the bolts in without much of a fight. Take a (I think it was 1/2", whatever size your header bolts are) wrench you don't really care about, cut it in half with a grinder, and you'll be able to tighten that last darn header bolt with much more ease next to the firewall. So once the fight is over, step outside, admire whatever view you have for a while, maybe walk over to the fridge, and then relax. Next, get your header collector hardware and gasket, and bolt up the headers to the exhaust. I thought about using rtv gasket maker on the header gaskets and collector gaskets to help really seal them up, but didn't, and it worked out perfect when I fired it up. So that's basically how to install headers in a later A body.
Electric Fuel Pump Installation
For installing an electric fuel pump I went with a low psi mr.gasket fuel pump. What was different this time is the factory fuel line layout compared to early A cars. I ended up deciding to put it on the out portion of the frame rail where you can see it behind the tire on the passenger side. There's either a vent or return fuel line that runs next to the main fuel line feed, so I bent both around and upward that used to follow the bend of the frame rail as it initially bent around, cut out a 8" section and installed the fuel pump. To mount, I grabbed the right sized drill bit that was slightly smaller than the diameter of the bolt threads, then ran the correct sized tap through the holes to give threads as the self tapping bolts didn't work out. Once installed, I ran a 12v wire all the way to my aftermarket relay box and added an inline fuse to the pump, the relay is tied into the ignition switch. Do not use teflon or any thread sealer on the fuel pump main filter as you screw it in, gas will melt that fast and gum things up quick. So that's how the fuel pump installation went on the Duster!
BATTERY RELOCATION
Since I didn't have much luck sourcing a Ram Van power steering pump that sits lower and allows you to keep the battery up front, the battery had to go to the rear. Bought a universal battery box, 25ft of 0 & 4 gauge automotive welding wire, painless main disconnect switch, and plenty of ring terminals + battery clamps. I chose to have the battery placed in the trunk on the passenger side with the theory of spreading the weight so there's not so much on the left/drivers side, especially when you are sitting there that it would affect cornering.
Bought some 1/4 - 20 bolts, washers, lock washers and nuts from the hardware store. First drilled 4 holes in the universal battery holder bucket, then marked them to the trunk floor and drilled 4 holes. Once it was bolted down, I started running the wires from the back to front. So I picked the positive post of the starter relay as my main power source for the front, and also added an additional starter relay next to it with a bridged + wire to add more connections as I ran out of threads on the first, plus it's a good idea to have a backup anyways. I added RTV/gasket maker later between the main + post of the starter relay and the solenoid wire that bolts on right below just in case if the nut ever comes lose and one of my hot + wires comes in contact with the solenoid wire, it won't spontaneously engage the starter, just like tripping both with a flat blade screw driver to bypass. I still used the standard starter wire, just cut the battery terminal off and added a ring terminal, then sandwiched it between the 0 gauge wire and 4 gauge wire. Probably would've been perfectly fine if I had just ran a 0, but was thinking I'd have the 4 gauge wire go from alternator all the way back to battery, and figured it made more sense to jump the alternators new charge wire right over to the starter relay to save more wire.. Either way.
Ran both the 0 and 4 gauge + wires to the main disconnect switch that I mounted to the tail panel, and added another set of 0 & 4 gauge wires to the aftermarket battery terminals. You'll want the best grounds you can get since the battery's in the back now. So I used a brush grinder to get a spot next to the battery box down to bare metal, added another bolt there with a 0 gauge wire for the negative side. For up front, did the same thing and ran the wire from inner fender over to one of the bolts that holds the AC delete bracket on. Also attached the factory negative wire on the firewall, passenger side over to the rear valve cover bolt.
Right next to the front's main negative wire that's bolted to the inner fender, I added another long bolt, this time 3" away and the bolt pointing outward into the wheel well so I'd have a lengthy amount of threads to add more negative connections to with ring terminals. I was pretty serious this time on how I did my wiring compared to the '65 Valiant's, had to go back and replace some wires and fix connections already due to using splices, no electrical tape, and just being in a rush back then in 2014, it really doesn't take long for connections to get corroded over time.
Take your time to do it right the first time! There's heat shrink connectors I like to get from eBay, you add both ends of wires and over lap them in the middle of the connector, then use pliers to crimp the metal ring in the center, and use a heat gun on the heat shrink to make it seal n' keep moister, corrosion out. Consider adding inline fuses to your new connections that pass through the firewall or go all the way back to the trunk, just in case in the event any thing happens your car doesn't burn to the ground. I also use electrical tape around all my new connections when I'm done working on them. That's pretty much how to relocate a battery to the trunk and wire it up! Hope this helps!!
3/13/2022: It's been a while since I've been back here on the site, planning on revising & adding some new info once again so stay tuned!
3/15/2022: Back in 2020 I snagged a 1966 Formula S Plymouth Barracuda that had a cracked block LA 318 installed. Long story short, sourced another 318 Magnum from a '90s manual dakota. Essentially did the same conversion over again and swapped it into the barracuda. There's a few things I'm going to talk about during the process of that swap. (More pics to be added soon..)
Serpentine belt system.
I utilized the serpentine belt system in this Mopar without an AC delete bracket, plus had manual steering from factory. To do this, I used my old serpentine belt tensioner pulley in specific to replace the idler pulley since I had already bought a new tensioner that came with a new pulley installed, as most should.. The special bolt washer had to be ground down on the washer portion to match the exact diameter of the bearing of the old tensioner pulley, that way it would be bolted up fine and still allow the pulley to spin. After a couple experiments with some serpentine belts, I found this belt 'Premium Multi-Rib 555K-7' in specific was the perfect serpentine belt to use. You can measure what belt you think you will need for your setup simply by using any automotive wire and wrapping it around your pullies in the same configuration the serpentine belt would be routed, it can be a bit tedious but it works. However, you have to remember to equate how far your tensioner travels as you're maxed out by using a wrench to see what your tension distance is, about 2" usually. So for example, you figure you'll need a 62" belt after measuring with your wire, but really it needs to be 60-ish" for the tensioner in the equation. Now, if you get a belt and it's slightly too long or too short, but may just get by, you can re-clock the tensioner's position in the bracket by drilling another set hole, 're-clocking' your tensioner, had to do this a few times with good success. It's nice going this route since it takes out another pulley to not worry about for future maintenance, and has no issues with tension. That's it!
Map gas is your friend when stubborn bolts won't come out, but use caution on what you're using it on. Plasma cutters are better if the bolt can't come out, had to do this on a caliper bolt that somebody managed to completely round the large hex head off in the past.. DON'T USE 12 POINT SOCKETS. Also use standard sockets instead of metrics, loser sockets cause problems. For whatever reason, Chrysler used quite a bit of metric hardware on these Magnums, more-so on the accessories bracket stuff.
Please feel free to leave some constructive feedback on this article or even message me if you have any, would love to improve however possible!
Don't cheap out, get a mig welder with 25%Co2/75% Argon gas, and throw that crap harbor freight flux core welder in the garbage!
Don't do this...
Websites that I recommend
Magnum Swap - (no title)
Schumacher Creative Services 'Engine Swaps' - Schumacher Creative Services
Summit Racing - Fast Free Standard Shipping on Orders Over $99 at Summit Racing
JEGS - JEGS High Performance Parts | Aftermarket Auto Parts & Accessories
eBay - Electronics, Cars, Fashion, Collectibles, Coupons and More | eBay
RockAuto - RockAuto
The Early Valiant & Barracuda Club - EVBC
The 1962 - 1965 Mopar Web Site - The 1962, 1963, 1964, 1965 Mopar Web Site Welcome Page
TTI Performance Exhaust & Headers - http://www.ttiexhaust.com/Shipping-Ordering/OrderingInfo.htm
SSBC Brakes - SSBC Performance Brake Systems
AMD Auto Metal Direct - Correct As Original Restoration Parts for your car or truck project.
Auto Body Specialties - Autobody Specialties Inc
Classic Industries - Classic Industries | Restoration Parts | Mopar Parts | Camaro Parts | Firebird Parts | Nova Parts | Impala Parts | GM Truck Parts | Tri-Five Chevy Parts
Layson's Restoration - LAYSON'S RESTORATIONS - DODGE, CHRYSLER, PLYMOUTH RESTORATION PARTS
Year One - YEARONE Classic Muscle Car Parts | Chrysler, Chevrolet, Pontiac, Mustang, Buick, Oldsmobile, GM Truck, Tri-Five, Jeep
Hot Rod/ Mopar Muscle - Mopar Muscle Archives - Hot Rod Network
MSD - MSD Performance Products | Tech Support: 888-258-3835
Autometer - AutoMeter Gauges - Quality - Accuracy - Built in the USA
My go to local automotive stores are O'Reilly & AutoZone.
Thanks for reading, hope this helps! Mopar or No Car.
