340 or 383?

[71ChallengerSE]

I have a question about which would be the better motor, I have a 318 that has 340 heads that needs to be rebuilt and I was wondering what would be the better, cheaper, easier option, go with a 340 or a 383?

I would like to get pretty decent fuel economy because I am going to drive the car almost daily.

Any info would be appreciated.

 

[Challenger6pak]

The 383 does not have the demand of the 340. When you say big block everyone wants the 440. This makes the 383 a relative inexpensive motor to come by. The 340 is a very desireable small block. This will make it more expensive than the 383. The 340 is lighter than the 383. Your car will have better all around performance (stopping, handling) with the 340. For a daily I would perfer the  340. It may be better on fuel than the 383. I would suggest making a list of what you want out of a motor for your car and then choosing the one that fits you best. These 2 motors may come down to an opinion call.

[matt63]

I agree with the last post.  I feel the big block is a better designed engine for numerous reasons including pan sealing, distributor placement, valley pan, external oil pump, head bolting and others.  I doubt the build cost would differ much.  If it comes down to mileage then perhaps the smaller cubes/lighter weight small block would win. 

[71chally416]

Hmmmm.....  The 383 is like the black sheep of the Mopar engine family. Most people opt for the bigger 440 or a small block, so you can pick one up for dirt. They are tremendously strong and easy to work on, but they have a rather odd long rod, short stroke/big bore combo that isn't really the best for making HP. The piston dwells around TDC a long time, relatively speaking. The good thing is any of the BB heads are much more adequate at feeding one than they are at feeding the much bigger 440 or stroker variants. When I ran one on the street I frequently got drug by both 440's in 2nd and 3rd gear, and some of the better running 340's that killed me off the line and maintained their lead. My worst defeat ever on the street was in my 383 '65 Belvedere vs. another '65 Belvedere that had a 440. It was rather embarrassing as the 3 guys in the back seat waved at me as he rapidly pulled away a few bus lengths. I soon afterwards got my first 440. That was in like 1975 

That being said, the 340 with a 904 tranny should easily get better mileage and it has a plethora of aftermarket parts available. It's definately a more desireable motor to have in the car at time of sale than the 383. The car will also handle, stop and hook up better with the smaller lighter motor. The stock small block head chambers are also far more detonation resistant than the stock BB that has the plugs in about the worst possible place and like much more advance (at least the 383 does) to run best. My          

[Bullitt-]

+ the added cost of converting....you would need a different automatic or manual bell housing & probably different length drive shaft

[Carlwalski]

340 sounds like the engine for you. I like 340ci engines. 

[360 'CUDA]

I think a better idea for you is to get ahold of a good running 318 or 360 from a doner car or junkyard and start with that.  Clean it up real good and put a four barrel manifold/carb setup on it.  You could put it together down and dirty style with stock dual exhaust and a 904 trans.

Being young and inexperienced you should putt putt around like that for awhile and not worry too much about 340s and 383s until you get some miles under your belt.  Almost everybody wrecks their first car and you don't want to be going too fast when you wreck this one..

[Chryco Psycho]

the other overlooked choice is a 440 crank & rods in the 383 block , this creates a wickedly light 426 CI

[71chally416]

How about a 440 cube small block? 
http://www.hotrod.com/techarticles/hrdp_0803_small_block_crate_engines/mopar_440_small_block_engine_modifications.html

[72bluNblu]

If you're concerned about price a 360 is the way to go. As mentioned earlier, 340's are sought after engines, and can be expensive. I found one, but I really just got lucky. I still paid $280 for the short block, the same guy would have sold me a 360 short block he had for $50! I bought the 340 because it was an early forged crank model and because its just got that nostalgic cool factor. Even having said that, the rebuild kits for the 340 cost more than one for a 360! And of course the 360 still has 20 more cubes. And if you're talking about a later 340 ('72 or '73), it will have a cast crank like the 360, so it really offers nothing other than the "cool" factor.

The 383 is also a cheap engine to come by, kind of like the 360 in that it is overlooked a lot. But, even if you can pick up a complete engine on the cheap, you'll still have to do the conversion for the transmission, either a whole new auto or a new bell and gear for a manual. And unless that 318 is hooked to a 727 you will need a new driveshaft as mentioned earlier.

Also, and this hasn't been mentioned yet, if you're running stock suspension for a 318 you'll need stiffer torsion bars and springs for that big block. A well set up small block car definitely outhandles a well set up big block car, but a car with small block suspension and a big block up front will be more than a handful. If you want to go big block and do it right, add new springs all the way around to the price tag.

I'd check the casting # on the 340 heads, most would fit a 360 with no problems. Then you just need to find a shortblock instead of a complete engine, since you'll be able to use all the 318's accessories.

[The Cuda Guy]

I like the 360, and agree with Chryco the 383/426 sounds like an awesome combo.  Good luck with what ever you choose.

Don

[Aussie Challenger]

  Stick with the small block unless you are prepared to spend an extra amount of time & money converting to a big block. Nothing wrong with the big block, I am not putting it down.   
  As said above , go with a 360, they are cheap, look at first glance to be a 340, plenty of performance gear available and they go increadbly well with a better mpg than the big block.      The earlier 360's will take your 340 heads or go for a later 360 which has a better head arrangement.       

[moparmaniac59]

As already been pointed out, I'd stay away from the 383 and either go with a 340 (if you want to stay nostalgic & year correct) or a 360 for a better deal on the wallet, Or go with a big block. The other option that's not been pointed out is buy a cheap low deck block 400 cid and buy a stroker kit. The kits are relatively inexpensive and you can get a ton of power from 451 cubes up to about 500 cubes. Chris, I've got a 400 (complete motor) from an old Plymouth Fury cop car I'd let you have for $150 bucks. So there you have it. A lot to think about. Mull it over and choose wisely!! Lots of good choices & none is really the wrong answer. It's all about what you want out of the car!!



                                                           Matt B.

[Challenger6pak]

I am building a Challenger that is going to be a second car which will see a fair amount of use. I am going with a 318 that is slightly modified with an overdrive transmission. The 360 will give more power and cost more to operate. Since my goal is to have some power and relatively decent gas mileage I chose the 318. How many miles will you put on your car in a year?

[sleepychallenger]

i never get a warm fuzzy when reading these threads. i know its not anyone really bashing the 383, but