340 or 360???

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6valiant5

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I have a 65 Valiant and I was wondering what would be the better motor to put in it. I want to be able to go out and cruise whenever I feel like it and know that whoever comes up next to me at a light if they want to race im going to stomp or if I go to the track I will get a good time. So what motor would be the best to get for that?
 
if you dont have either engine...the 360 is going to be cheaper to get and cheaper to build and Probably get better performance...
 
Yea I dont have either im asking so I know what to get. Just wondering why a 360 would be cheaper? Now since it is a 360 means it should put out more power right?
 
i think a 360 would be cheaper, because they were built more years, and 340's are pretty pricey
 
6valiant5 said:
Yea I dont have either im asking so I know what to get. Just wondering why a 360 would be cheaper? Now since it is a 360 means it should put out more power right?
Click to expand...

The 360 is easier to come by that is why it would be cheaper! They come in LA or Magnum.............Take your pick!!
 
you can find 360s in the junkyard pretty cheap...you wont find a 340 in a junkyard cheap...

so the initial cost of the engine is going to be hundreds of dollars cheaper for a 360...

the piston selection is better and cheaper for a 360..
KB107 pistons are probably the best buy on pistons you will find...light..flat top with good compression..
 
Ok sweet thanks for the info. Would you say it would be smarter to try to find a 360 and rebuild it and make it badass or try to find one that is pretty much ready to go? Just wanting to make sure, a 360 will fit in my Valiant?
 
valiants came with 318....then 360s fit... same external dimensions.
 
It really all depends. If you find one that is already a bit souped-up but hasn't been thrashed too hard and has good compression and oil pressure then by all means take it. HOWEVER the condition of the bottom end is more important than the HP stuff in the top end; try to find the lowest-mileage, least-abused engine you can whether or not it has any hop-up parts in it.

Oh and by the way the 340 and 360 are small blocks, not big blocks (those are the 383, 400, 440, etc.).
 
The 360 is definitely the cheaper and easier way to go. A 340 will be hard to find, expensive, and even more expensive to build as noted already.

The 360 is a great engine and very common, easy to find parts for, and will make just as much if not more power. As far as running or build it yourself, it depends on what your plans are for the car. If you want it running fast, don't have much cash or don't have any big race plans, finding a running 360 isn't a bad way to go. Be sure to inspect the engine as best as you can, preferably hearing it run and checking compression and the like. Ultimately, you won't know much about the engine internals, so when it comes to making performance modifications you'll want to keep it pretty mild. But not a bad way to go for a driver-level engine.

If you're looking for big horsepower or have more cash on hand, build it yourself. That way you know exactly what you've got and what its capable of. You should also know its in for the long haul, as opposed to a runner that you don't know the history on.

But I've seen complete, running 360's for under $500, a rebuild will probably cost you at least $3,000 just for a "stock" rebuild, more for high horsepower.

Ultimately your budget and plans for the car will probably make the decisions for you.
 
they are both great motors. but in my opinion i think your better with a 360. like already stated they are a lot cheaper to purchase. then you also get an extra 20 cubic inches right off the bat which is great on the street. my lil 64 valiant would go 14.0 with a stock 78 360 with eddy performer intake and 273 exhaust manifolds. with the spitfire headders they make now it would have been in the 13's easy. not super fast but very fun for a street car that you could drive anywhere.
 
Yeah son as it was stated here a 340 will cost a bunch if you can find one...I know we talked about 318's for your car.. They are good little engines as you know from my Dart, but for hp the 360 will give you more options.. But you will have to figure out your budget and see what will fit it...
 
Ok that helps a lot and I will get a 360 to put into the Valiant. abodyjoe thats what I like to hear about the one that you had. I mean 14s is fast especially for a stock engine. Im going to get a used one and just use to for being able to have power but when I get the money I will start to rebuild it cause I dont have $3000 off had to be able to rebuild it as stated. Now I just need help finding a decent 360 lol
 
bOb shingler said:
bigblbock a-body tech :sad:
Click to expand...

I second that!?

One thing to concider. If your cr is a /6 car, you will have to get a new tranny too, among other items. If it is an Auto 273 V8, you will need a new T.C.

But a 360 aint no BB

Phil
 
Since you've decided on a 360, it would benefit you, I think, to look at the advantages of the L-A vs. Magnum motors, and vice-versa.

The Magnums were introduced in 1992 or '93 (can't remember), so they've been around for at least sixteen years... plenty long enough for the junk-yards to be full of them. That brings the price down.

The two engines are very similar in most respects, but there are some parts that were changed when the Magnum version came out that bear mentioning.

The lastest-year L-A 360s had roller lifters, beginning in about 1986, I think.... check that out for accuracy. I'm not sure when they started.

With the oil situation being what it is as regards missing ZDDP (zink) in a lot of oil, rollers are a very desirable consideration, since they don't seem to need the missing ZDDP to live a long time. Cam longivity has sometimes been a problem with flat tappet cams since the ZDDP debacle. Magnum 318s and 360s all have roller lifters.

Magnum heads are seen by some as being superior (at least, on the exhaust side) to the best stock L-A heads, but I don't think it's been proven, and when discussed, doesn't seem to be a large improvement in terms of flow. Again, this is arguable. They're not going to flow like an Edelbrock or a W-2.

If you buy a junkyard Magnum engine, in my opinion, you should try to buy it less the intake and fuel injection system. The stock intake manifold is not a very good one, and there are several really good 4-bbl intakes available (Air Gap, etc.) that, along with a 750cfm carb, can replace the electronic fuel injection system and will greatly simplify the installation (no computer necessary.) You'd need an electric fuel pump, or install a pre-Magnum front cover on the engine and add a fuel pump eccentric-extension to the nose of the Magnum cam (available from Hughesengines.com.)

Headers are available for this swap, with everything from the el-cheapo Spitfire model to the expen$ive TTI setup that is a bear to install, but is arguably the best available for this swap, once it's "in."

If you don't want to have to do a major amount of fabrication on the rear mount, then stay away from the 4-speed overdrive automatics. They are great to have, but are a pain in the butt to install because of the physical size of the overdrive unit in the tailshaft. A lot of floor-pan and rear crossmember surgey is required for the install.

If you stick with a 904 or 727 3-speed automatics, everything fits pretty well, as is. There may be some floorpan issues with the 727; I'm not sure about that. A manually-shifted 4-speed is another option, but I hear that clutch linkage can be a bear, with the available headers. Years ago, I built a 340, 4-speed '64 Valiant, but I ran fenderwell headers, so clutch linkage was no problem, then. (Most fun car I ever owned!!!):cheers:

The L-A engine can be a good "buy" because there are literally millions of them out there, but if you get one, my advice would be to try to get one with the 1986-up roller cam setup; you can't easily add a roller cam setup to one that came originally with a flat tappet cam. The lifter bosses in the block are different...

The flex plate or torque converter will have to be specially balanced for the 360 as it will need to have the correct "un-balance" weight, as all 360s are "externally balanced", with the out-of-balance spec being different between the L-A and the Magnum. B & M makes flex plates with the correct amount of imbalance for these engines; just be sure you get the right one, or, you'll have a "shaker."

My car is a ;72 Valiant 4-door, about 300 pounds heavier, I think, than a '65. With a 1998 360 Magnum with only a very mild roller cam and a set of T-A Drag Radials, and a 3.90 gear in back (stock 318 converter) and a Hughes cam, it ran 13.35 @ 102 mph on a 95 degree day at sea level. It was spinning badly, with only a 1.91 50-ft. time. That was with 340 cast exhaust manifolds, running through the mufflers.

It would be no trick at all to drop your '65 into the high 12's with an almost completely stock motor.

You might consider a crate motor... or, not.

Good luck, and keep us posted!!! Early A-Bodies are my personal favorite of all Mopars...
 
I have had several small block early a body cars. The only problem I had with a 360 in a 66 valiant. The oil pan from a 273 wont fit on a 360 and the 360 oil pan didn't fit very well in front by the K member. I use a BFH and clearanced the oil pan as best I could...it still hit the K member and would vibrate. There was probably a better oil pan to use. The 273 oil pan will fit a 318 and a 340 just fine. I no longer have that car. I am currently working on a 65 valiant. I will probably build a roller cam 318 with 302 casting heads and a 4" stroker crank. The combo makes 390 inches and I can make it look like a 273 Commando.
 
You'd be better off building the 340 or a roller cammed 318 block with a stroker crank, for a possible 392 cubic incher. Your options with either of these blocks is the standard main journal size,which means you don't have to have a special oil pan. Chrysler castrated the 340 to build the 360. Bad choice,no wonder they've been bankrupt TWICE. Espescially if you can find a good 340 block and they are out there,you can, if you stroke it, build a larger combo from the 340 block. 360 blocks, in my opinion,make excellent boat anchors,due mainly to the facts of the larger mains, thinner cylinder walls, external balancing needed, and on and on. Remember,this white elephant was designed to please the smog people,at a time when we already had something that worked just fine for a perfomer small-block. Look further at the faact thar Mopar brought the 340 block back,as a replacement block. I think that, in itself, speaks volumes. 360' are a good motor-home or pick-up engine,real performance, although it costs a ittle more starts,where the factory did in '68, with a 340 block and good heads.
 
If you want to race a Stock Class drag car, or build a killer, high specific output motor for NHRA's Competition Eliminator, a 340 is undoubetdly the better of the two for you. However, the 360's that run in NHRA's Stock Eliminator run just as fast as the 340s, even in Super Stock, but the 340 is obviously easier to go fast with, because of the higher OEM compression (pre '72) and bigger valves, not to mention having a shorter stroke and less piston speed at any given rpm. The 340 is just a better high-rpm motor.

Think of the 340 as the best basis for a race motor; the 360 as the basis for a cheaper-to-build, street/strip motor.

It's not that hard to build a 500hp 360,and the parts are a lot earier to find, and cheaper than 340 stuff, for the most part.

The 318/360 Magnum heads are not very good, admittedly, but both Magnum blocks have OEM roller tappets (as do some of the '86 and up L-A 318/360 motors), but if you want a roller in a 340, you have to install an aftermarket setup, and that can get expensive.

Oil pans are not at all hard to find for 360's... I bought mine (for use in a '72 A=Body car) from P-A-W, a big, aftermarket mail-order parts store, online. It was in their ad in Hot Rod magazine.

The extra torque from the 20 additional cubic inches that a 360 has over a 340 is useful on the street, as is the extra horsepower it generates.

They are two different ways of getting high performance; 340's for serious racers, and 360's for people like me, who want to go maybe not quite THAT fast, on a little less generous budget.

There's plenty of room for both... :)
 
Yea the 340 would be nice but to spendy for my budget. I want the 360 to have the power and torque on the street and if I decide to take it to PIR(the local drag race track) I will be able to get good times and show off the car, then drive home and if someone wants some dominate them.
 
seriously...

all thing being EQUAL, the 360 will win everytime...

more torque from longer stroke....lighter pistons...
 
branczdad said:
You'd be better off building the 340 or a roller cammed 318 block with a stroker crank, for a possible 392 cubic incher. Your options with either of these blocks is the standard main journal size,which means you don't have to have a special oil pan. Chrysler castrated the 340 to build the 360. Bad choice,no wonder they've been bankrupt TWICE. Espescially if you can find a good 340 block and they are out there,you can, if you stroke it, build a larger combo from the 340 block. 360 blocks, in my opinion,make excellent boat anchors,due mainly to the facts of the larger mains, thinner cylinder walls, external balancing needed, and on and on. Remember,this white elephant was designed to please the smog people,at a time when we already had something that worked just fine for a perfomer small-block. Look further at the faact thar Mopar brought the 340 block back,as a replacement block. I think that, in itself, speaks volumes. 360' are a good motor-home or pick-up engine,real performance, although it costs a ittle more starts,where the factory did in '68, with a 340 block and good heads.
Click to expand...

I don't know about that. Take a 70s 360 with J-heads and add dual exhaust, 4-bbl. on a good intake, a mild cam and (maybe) a compression increase and you have an engine that is almost exactly the same as a 340 but with .27" more stroke and .040" less bore (and tq/HP peaks at lower RPM's). Even a stock long-block 360 Magnum with only dual exhaust and dual-plane intake will easily make over 300 net HP. Besides, like said before things like replacement pistons for 360s are more plentiful than those for 340s.
 
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