heads

[hoss]

I have a set of heads off of a 1965 383, and also a set off of a 72 400, could somebody tell me which set would be better and why?

[DartGT66]

The old 383 heads are closed chamber heads. They have smaller combustion chambers, smaller valves and ports then the newer heads. As bare heads, the '72 400 heads are a clear winner. However, you will loose some compression ratio using these heads, they should be milled about .050" to make the CR equal. However, if the block you have has about zero to .020" piston top to deck clearance, the closed chamber design becomes more interesting. If you have over .040" deck height there is absolutely no reason to use the closed chamber heads. If your deck height is less, you could take the bigger valves out of the '72 heads and have them installed to the 383 heads, and then pocket port them using the MP templates. This way you would get heads that flow decently and get a good quench chamber, which is good for making power and to fight detonation.

[hoss]

That makes sence, thanks for the imput. I took the forged crank out of the 65 383 and plan to install it in the 400, just wanted some insight on both heads, cause I have both engines complete. I hope in the end to get somewhere around 350 to 400 Hp after all said and done, I think with helpful people like you it can be done!