Ol' Blue's magnum swap

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Blackhatguy

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I've decided to make a bona fide, dedicated post about my upcoming engine swap, for which this forum has already been immensely helpful. not only for information, but in my hunt for parts as well. My main problem though, is that all of the information I needed to know I had to hunt through hundreds of threads to learn. I wanted to try and consolidate as much as I can here in this thread to not only look back on, but possibly help anyone else by saving them some time hunting. A lot of what I am about to post may seem painfully obvious, but I was a complete newbie just a few months ago and so it was painfully obscure to me at the time. So without further Ado, here goes.

I'm working with a 1964 Dodge Dart, two-door hardtop.
Slant 6 engine, 904 auto transmission, push button shift, 7 1/4 rear end.

Engine I'm working with is a 2001 5.9 Magnum. I am unsure as to exactly which vehicle it came from, the oil grommet on the valve cover leads me to think it may have come from a van though. That may be a problem finding an oil cap, we will see.

For starters, if you have a Magnum engine you are stuck with Magnum heads, unless you want to spend some money on machine work to drill out the oil galleys. This is because Magnum engines were redesigned from the LA engines to oil through the push rods rather than the shaft style rocker.
The upside to the Magnum head is that it is to the Mopar small block as the vortec head is to the Chevy, one of the best flowing production heads you can get for that motor.
The downside is, those same production heads are prone to cracking in that little space between the intake and exhaust valve. There are a few beefier aftermarket replacements but that is still extra money.
The Magnum block has a slightly different deck height than the LA engine. It is a little bit lower, and LA pistons will come out the top. You have two options here, use the original Magnum style pistons and deck the block to get the proper quench height, or use LA pistons which will stick up past the deck a little bit. You can then use a .050 head gasket to keep the head a safe distance away and you will wind up with .032 quench height.
The Magnum engine also takes a roller cam, and that is going to cost a little bit more, but it's worth it because of the much higher ramp rate. That gives you more area under the curve for valve lift for a given duration, meaning the power of a bigger cam than the numbers would suggest.
You will need to decide now if you are going to run an electric fuel pump or mechanical, because if you are going to run a mechanical then you need a long snout cam and fuel pump eccentric.
The intake manifold bolts are at a different angle, so you will need a magnum specific intake manifold for it if you are going to carburate it.
There are three different timing covers you can use, and it is at this point you will have to decide before you even start your build whether or not you want to go with the serpentine system that comes with the 5.9, or if you are going with the older V belt design. Unless you are looking for the authentic look of period correct V belts, keeping all of the accessories off of the Magnum donor vehicle will help you immensely. In that case, keep the magnum timing cover and water pump. You will have to have an external electric fuel pump for it.
If you are going to do the V belt set up, you are going to have to get one of two other timing covers. Pre 69, the timing cover has the timing marks on the passenger side and the matching water pump has it's suction on the driver side. Post 69 that is reversed. This will be important because that affects accessory bracket fitment and radiator selection. You cannot mix and match from either side of that date. Pulleys will not line up.
If you are adding a larger radiator 3 cores or larger and hoping to stay with a mechanical fan, you will likely see your fan clutch hit the radiator. A good solution is a fan clutch from a jaguar, and a universal clutch fan. See picture below.
The 5.9 Magnum is an externally balanced engine and has a 5.9 Magnum specific harmonic balancer. If you are doing V belt accessories, you will need to look for an earlier model 5.9 harmonic balancer that is two piece without the pulley permanently attached. Doorman makes it. This will allow you to bolt on the V belt pulley. There may be one hole that does not quite line up with the rest, just use a file to slightly enlarge the hole so the bolt will go in to the balancer.
Reuse the flexplate or flywheel that came with the engine, make sure that the flexplate is weighted so that you can use a neutral balance converter.
1960 to 1967 the torque converter pilot has a smaller shaft than 1968 and up. You will need a bushing to take up the slack.
If you are converting a model with a slant 6, the Transmissions do not share bolt patterns with the V8 and you will need another.
Also, if you plan to keep the push buttons you will need a 64 or 65. If you get a 65, you will need to install a 64 valve body. You can use your slant 6 transmission as a donor.
The first two gears in the slant 6 are lower and you can swap those into the V8 transmission as well to make up for highway gears if you want to run them.
The output shaft on the early transmissions do not have a traditional yoke and U-joint, they have a trunnion. Having a transmission shop swap that out for a more contemporary output shaft will help you find replacement parts more easily in the future.
The lowest price I have found on headers so far has been with Sanderson model DD9. They are shorty headers, and only specced for early A bodies with auto transmission. They are only available with 1.5 inch primaries, but they fit tight with minimal fuss.
Your fuel delivery line will need to be upsized, the one provided with a slant 6 is not going to provide enough fuel for anything over 250 horsepower. You will burn up your electric pumps trying.
The 5.9 block has kept LA style engine mount bosses, but they have been slightly modified. There are two holes up front, and one hole in the back. You can use 318/273 mounts, but you will have to add a half inch spacer on the driver side back bolt to take up some slack, and on the passenger side you will have to weld a new tab on to the front of the motor mount because it only has one bolt hole there.
You will need a 360 LA car style oil pan and pickup. You will also need a new dipstick, the one for the truck pan will not work in the car pan.
You can reuse the Magnum starter, in fact that is required for use with headers because they are so much smaller than the old style.
You will not be able to reuse the Magnum distributor, but an LA distributor will drop right in. There are a few companies making GM style HEI distributors. That is what I am using. They take GM replacement components and a 4 pin ignition module.
The spark plug wire set will be the same 5.9 said you would have bought for the donor vehicle.
If you are reusing the Magnum distributor hold down clamp, you may have to grind a little bit off of the inside where it contacts the shaft of the distributor in order to get the bolt in the hole.
There are two different thicknesses of rubber motor mounts, the thinner one lets the motor sit down a little bit lower for better hood clearance and firewall clearance to distributor, but if your car came with a slant 6 you will want the taller one so your oil pan will clear the center link on your steering.
V8 cars came with thicker torsion bars and one more leaf in the rear springs. That is so the front can carry the extra hundred pounds for the engine, and the rear can handle the extra torque without collapsing the springs.
The 7.25 rear end is marginal past 200 horsepower, seriously consider upgrading. I'm going with a Ford 8.8 personally, sacrilegious I know but they are plentiful, as are aftermarket parts. And they are every bit as strong as the lauded mopar 8.75.
The Slant six throttle linkage is incompatible with V8 carburetor orientation. So is the pedal. Those will need to be swapped out for a V8 pedal and cable linkage. Also, a Mopar specific kickdown cable linkage will be needed.
Stepping over 350 lb of torque, consider subframe connectors.

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Im gonna be doing the same thing in my 63 come spring and this helped alot. Couple of questions, where did buy the headers from and are you using a V8 center link. Also which intake manifold it that.
 
THIS^^^^^^^^^^^^^
Wonder if they can be modded to work with 4speed..............


D
 
Im gonna be doing the same thing in my 63 come spring and this helped alot. Couple of questions, where did buy the headers from and are you using a V8 center link. Also which intake manifold it that.
Your 1963 never came with a V8, so the firewall is going to need to be relieved where the distributor is going to go. If you use B body isolators such as from the Barracuda they will lift your engine above the center link far enough that you don't have to Dent your oil pan or change the center link. The manifold I'm using is a knockoff of the Edelbrock Magnum air gap, it's about $120 cheaper and dual drilled for the old style and Magnum bolt patterns. I bought my headers through Century performance
 
THIS^^^^^^^^^^^^^
Wonder if they can be modded to work with 4speed..............


D
They certainly can, all you have to do is make sure that you pulled the donor engine from one that was already stick shift, so the pilot is drilled out. Otherwise you could take the crank to machine shop and have them drill the pilot for you. Everything else bolts together with LA parts. Once again though, make sure that you use the flywheel waited for the Magnum engine unless you are going to take the rotating assembly to the machine shop and have it neutral balanced like a 318, if you do get it internally balanced then you can run a neutral balance flywheel and harmonic balancer
 
Some early Magnum blocks do have the LA head oiling holes drilled in the block. Those early blocks can get LA heads installed if someone wanted to go that route. Not sure when the holes were no longer drilled, but I have seen several 1994 model trucks with those holes present.
Also, the engine mount bracket lugs on the Magnum blocks were not modified, they were basically carried over from LA production. The smaller 273 and 318 LA engines uaed one style, and the the 360 LA used a slightly different width on one side. I think 340 was same as 360.
Just thought I would add a little to this. Really like the car. Keep up the good work.
 
Some early Magnum blocks do have the LA head oiling holes drilled in the block. Those early blocks can get LA heads installed if someone wanted to go that route. Not sure when the holes were no longer drilled, but I have seen several 1994 model trucks with those holes present.
Also, the engine mount bracket lugs on the Magnum blocks were not modified, they were basically carried over from LA production. The smaller 273 and 318 LA engines uaed one style, and the the 360 LA used a slightly different width on one side. I think 340 was same as 360.
Just thought I would add a little to this. Really like the car. Keep up the good work.
When I tried to put on the LA style engine mount on the passenger side, I found on the block casting only one hole on the back making 3 total instead of 4. Unfortunately for me, the upper hole is there but not the lower hole. On the front of the block both holes are there, but the mount itself only has one hole. That left me with only the top two holes with bolts in them and a wobbly mount. What I had to do was cut the triangle with the bolt-hole off of the back of the mount and weld it to the front of the mount so it could bolt to the block with both front bolt holes. As far as the oil passages go, I think 94 would have been the last year that you would find them. If I'm not mistaken, they quit casting them and 93 and used the leftovers until 94.
 
They certainly can, all you have to do is make sure that you pulled the donor engine from one that was already stick shift, so the pilot is drilled out. Otherwise you could take the crank to machine shop and have them drill the pilot for you. Everything else bolts together with LA parts. Once again though, make sure that you use the flywheel waited for the Magnum engine unless you are going to take the rotating assembly to the machine shop and have it neutral balanced like a 318, if you do get it internally balanced then you can run a neutral balance flywheel and harmonic balancer


I was referring to headers pictured. My 5.2 has pilot hole...Thanks
 
I was referring to headers pictured. My 5.2 has pilot hole...Thanks
My apologies, in that case, the only thing preventing them from being used in the manual transmission is the fact that they point the exhaust straight toward the z bar. If you convert to a hydraulic clutch, you can route the hydraulic line well clear of the exhaust.
 
I got a little more done today, and took some more pictures, but I have a favor to ask... Would somebody here with a factory V8 mind measuring the distance from the K Frame to crankshaft centerline for me? Also, would you mind measuring the distance from the center link to the oil pan? I'm having a really hard time finding a V8 center link, so I went with 1964 Barracuda motor mounts. They are about an inch thicker. I may have trouble with hood clearance, but I plan on getting a hood scoop anyway. Mainly I just want to make sure I have enough room with those thicker motor mounts to clear the Slant six center link.

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Got some good news from Pat Blais, 65 904 will work with the dash button shift mechanism, so I got the bushing on the way. I also filed the magnum flex plate hole to match the 65 converter. Mounted up fine.
Found out that the magnum balancer sticks out 1/16th further than the 273 version, so I had to shim the water pump pulley out to line them up.
 
Balancer and pulley installed, and I finally found out that all I had to do was pull the rubber grommet out of the valve cover and the oil cap from the truck screws right in.

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Shop finally got done with my carburetor! A simple rebuild I could have done myself, but apparently the previous owner had a bunch of leftover parts he threw together with Reckless abandon. Cost me $200 to get it redone, but now at least I know everything matches and works.

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Looks a little tight? Were you able to get set down completely in the mounts?
 
Yes I was, but it turns out those headers really needed to go on a manual steering car. I got them to work, but it would have been better if I had manual steering. I end up going with the taller barracuda isolators and I don't think I could have got it done otherwise.
 
Yes I was, but it turns out those headers really needed to go on a manual steering car. I got them to work, but it would have been better if I had manual steering. I end up going with the taller barracuda isolators and I don't think I could have got it done otherwise.
With the taller insulators are you going to have adequate bellhousing to body clearance?
 
It looks like I am, I will know more when I get the crossmember back in place. But for now, when I am under the car I can push up on the tail shaft until it touches the floorboard so it doesn't appear that anything is touching before then
 
Apparently the long tail shaft is an inch and a half different than the short tail shaft as far as the crossmember mount goes.

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I'm down to the tedious parts now, still have to get the driveshaft shortened since I'm using a long tail shaft transmission... But working on wires right now.

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instead if that bushing can't you just change the pump in the trans and all then use a 69-up converter? it would open ya up to a lot more options converter wise and i believe cheaper too... :)
 
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instead if that bushing can't you just change the pump in the trans and all then use a 69-up converter? it would open ya up to a lot more options converter wise and i believe cheaper too... :)
That's a mighty fine idea, and I had also been wanting to change the output shaft to the splined version as well. But, all that's going to have to wait for a lot more overtime than what I've been getting. I emptied my wallet getting the engine in there, the transmission is going to have to wait a year or so before it gets any fancy work done to it.
 
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