318 or 340?

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Jplush

Jplush

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I just picked up a '68 B'cuda convertible. She's a complete rebuild, automatic. I need to get a power plant for her. I'm new to Mopar and am not sure to look for a 318 or 340. Gonna be a street cruiser, no need for anything ridiculous; I just want something strong that sounds good.
 
360 all the way. 318 is fine for a cruiser but is dimensionally identical to a 340/360 sans 1 bolt boss. A 340 will break you financially. 360 has more torque and that is what makes a street cruiser fun. If you already have a 318, you can build one but its literally the same price as a 360 build. 318 with a raspy cam and headers SOUNDS as mean as a 340.
 
New to Mopar? if that is the only two your considering, the 340 is more expensive/harder to fine. 318..... dime a dozen. 340 will make your car worth a little more, offer more potential in performance. 318 will work great for the money and offer a lot of performance. Should something "go wrong", better to be out a 318 than a 340.
I would consider a 360 in the mix for sure...... Great performance, dime a dozen
 
I was in the market for an engine when I heard a Dodge Ram with a 360, cam, exhaust some simple stuff ohhhhh boy. I can't freaking wait to get the valiant done and put in a 360... Deals can be found, lots of durangos are out and about.. In my area it's 500 for one with a bad tranny, I managed to get one for 400 good everything just needed a ECU. Worth the peace of mind knowing it runs good before you put in the labor.. The main thing to plan for is cracked heads, I've heard it's common in the 360 magnums
 
Yes, this is my first adventure that is not a small block Chevy. I appreciate all of the best bout so far. I will definitely look into the 360 option.
 
Three4D$$$$$

stroke a boneyard 360 for the same cash. Fouroh8!
 
The initial cost of the 340 is what will get you, good parts for all of them cost the same.
 
If I had things to do over, I'd probably just start with a Magnum, either a 5.2 or 5.9. Here I am working over what amounts to a 360LA roller block with EQ heads, so "same difference" pretty much!!

340s have what is nowadays a "false" mistique. That is, just to say you have a 340, and get "oohs and ahhhs" from people who remember what the 340s were. In this day and age, "buying" one will set you back for that reason, and not necessarily any actual gain. .........Which is why folks are suggesting a 360

So you need to decide.........what you want.......

Just a nice cruiser? 318 is fine. Or if you get a 318 CHEAP you can build it anyhow. You won't be payin' extra for "magic" 340 heads which are no better than 360 heads.

An LA can be made to look "period correct" if that is important to you.

Or you can put a magnum in there.........
 
1970dartcustom said:
383!!! :burnout:
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And a 383 is NOT a chevy dammit! :banghead:

By the way, 383 B block has my vote as well.

Since you don't have an engine for your vert yet, just buy a 5.2 or 5.9 magnum since you plan to use it as a cruiser.

I'm currently running a 318. It's apart right now for an in-car cam (owmybackhurtswhere'stheibuprofin) and head swap. It still had the plastic gear teeth timing chain, so that went in the trash. So did the factory cam and lifters. Got a nice shiny new left side timing marks 5 pound timing chain cover to replace the old right side timing marks 5 pound timing chain cover.

Could I have put the cam, valvesprings, heads, timing chain, water pump, timing chain cover, intake manifold and carb on a 360? Hell yes, but the 318 is what I had to work with, so I'm beefing it up for now. After I get the car back on the road, and when I can find a 383 block local and cheap, then I can get to work on that.
 
Ottmundr said:
And it's NOT a chevy dammit! :banghead:

By the way, 383 B block has my vote as well.
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why ?
if your going to suggest a big block why not go with a 440?

I still say 360 is the best/cheapest/easiest-to-find/powermaking option
 
diymirage said:
why ?
if your going to suggest a big block why not go with a 440?

I still say 360 is the best/cheapest/easiest-to-find/powermaking option
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The 383 B and 400 B blocks are a little narrower. I prefer the red-head stepchild 383 just because I'm a bit contrary =) If you apply the 451 Manifesto to the 383, you aren't too far off from a 440 if you punch it out some. :D
 
A good 5.2 Magnum will more than suffice for what you want. You can find one WITH warranty from an LKQ near you. Just add your choice of intake, exhaust, carburetor and distributor.
 
I'm going the 440 route. I did think this through and was considering a small block. After much looking and reading I came to the conclusion that I'd have no issue with a 318. I know the 340 is heralded as THE great small block but unfortunately that reflects in everyones asking price. i wouldn't pay $500-1000 more for 22 cubic inches. Iv'e seen many strong 318s running nice on the street.
 
If I had only those two to chose from, it would be the 340, even if I had to put all teener parts on it. I once built a combo that way, and a 340 with a teener cam and 2bbl top-end is still stronger than a straight teener. I called it my big-bore teener.

But If I was limited to any small block, it would be the 360. The extra stroke allows a little more cam before the Dcr falls off. Or cam for cam; more everything,including mpgs.I would pay extra for the 360, and you couldn't give me a teener.In a well-built DD with a small cam, you will save the cost of the 360 core in better mpgs alone, probably in the first year;certainly in the second.
But in a streeter, I wouldn't be in a hurry to put a big cam in it. Cruising at sub-1600rpm with an O/D, and ripping off low 12s, all while getting hi 20's mpgUS,( I got up to 32USg),is kindof intoxicating. Just try that with a teener....not even two out of three.
Your vert will thank you for the extra cubes.
 
318/340/360 383/400/440 there all great engines all will do job, I'd probably go 383 it's an engine no one really cares about millions were made can be found reasonably.
Drop a 440 crank in her there a dime a dozen especially cause everyone's going stroker. You'll end up with and engine that's slightly smaller than a 440 at 429-431 cid but it will lighter internally and externally and slightly smaller dimensions that the 440. 750, air gap some stealth heads, headers and a 220-230 hydraulic roller cam.
 
Most of the 340's that are out there are almost at the limit of overbore...

I would go with a 318 or 360...
 
I have seen 340 blocks on this very forum for a reasonable amount of money. The 360 has plenty of issues although most guys tend to ignore them. The bores are .040 smaller. The main bearings are big, even for a 4 inch stroke. The stroke is longer so the rod to stroke ratio starts looking like a small block Chevy.

One builder just built a very mild 340 and it produced impressive numbers. You don't have to spin the guts out of it either. No matter what, you can never fix the bore issues, or the main bearing size issue.

Spend the money on a 340. If done correctly the 340 will out run the others all the time. If you decide to do a stroker, you still have the bore size.

I am not a fan of the magnum engine, of its Chevy rocker system. I know guys like the magnum because you can drop in a hydraulic roller cam. I was big into them a while ago, but I have gotten off that band wagon. I would rather run solid lifters or use a hydraulic roller stick with solid rollers on it. They make more power, rev higher and last just as long. You use almost no lash and it works.

Just my opinion. I'm sure the grey whisker crowd will be along to chastise my opinions.

Do a 340 and don't look back.
 
A 340...this ain't 1971, other than the purists nobody is going to be impressed. Stroke a 360....and if you really feel the need to impress some buckethead just lie.....ain't like there is any visible difference
 
I do agree with yellow rose, the 340 is preferred. I just have never seen a deal come up that warrants it over the 318. Asking prices on a block alone for a 340 tend to be so hyped up. Hopefully a FABO member can hook you up with a realistic priced setup. If not don't be afraid to go the 318 or 360 route.
 
yellow rose said:
I have seen 340 blocks on this very forum for a reasonable amount of money. The 360 has plenty of issues although most guys tend to ignore them.

Just my opinion. I'm sure the grey whisker crowd will be along to chastise my opinions.

Do a 340 and don't look back.
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I'm on board. More than my whiskers are gray.
 
I think the point that can be taken here is that all these engines can be made to work, perform, and are durable. Many 360's are running low E.T.'s, and do it consistently and are reliable. 318's are fun and very reliable. They have more potential than most will give them credit to have.....
I personally think strokers stress the block a lot, especially if your beat'n on them every weekend.... but that's just me
 
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