1978 440 heads vs 1964 383 heads

[Trebor67]

Hello everyone. Im sure sometime in the past this has been discused, so I apologize now for re hashing this debate. As I have a 1978 440 , virgin engine. I know that these years were extemely low combustion engines. I am doing a very mild build. So I am debateing on useing the 383 heads to bump up the compression. They have a closed chamber and as far as the valves go it has a slightly smaller exhaust. Which when re conditioned I would have it bored to a larger valve size. My question is what would any of you choose to do? Thanks for the input.

 

[66 coronet]

What is the casting number on the 383 heads?

 

[Hemi Rebel]

I would go with the 452's. They have hardened valve seats and 15 years of technological improvements.

 

[moparmarks]

I myself like a closed camber but the 452's will flow alot more and be more durable then the 516 heads.

 

[Meep-Meep]

The 516 and 452 pretty much have the same intake port shape, which is a flat floor and is inferior to the 915 and 906 heads. However, the closed chamber will add nearly a half point of compression, and if you use the steel shim gasket you can almost get another half point. I'd go with the compression increase of the 516 head but add the 1.74" exhaust valve like you mentioned.

 

[racedodge]

The 516 and 452 pretty much have the same intake port shape, which is a flat floor and is inferior to the 915 and 906 heads. However, the closed chamber will add nearly a half point of compression, and if you use the steel shim gasket you can almost get another half point. I'd go with the compression increase of the 516 head but add the 1.74" exhaust valve like you mentioned.

BINGO!!! I did this with some 516's, 2.08/1.74's, works great.

 

[Cranky]

I've done the same thing with a set of 516's for a stock bore 440 with a Hemi grind cam. It's still sitting on an engine stand waiting for something to go in.

 

[Trebor67]

Thanks guys, really good advise. I agree with what everyone said, If I had the 915 or 906's, I dont think there would be much debate, I would use them. But with what I have and the fact that both sets have to be re-worked. Im leaning towards the 516's. But thanks guys for your input. It adds a little more confidence to the decision.

 

[Meep-Meep]

Given the choice of a better port vs. raising the compression of a late 70's 8:1 motor I will always choose compression because you can't argue with physics.