I've got a bit of a Frankenstein engine - it is a 1972 440 block, but it has a 1959 383 4-bbl manifold on it. These very early 383 manifolds were actually for a 383 RB block (only in 1959 & 1960 I believe), so it fits on this 440 block quite nicely without requiring gaskets / spacers.

So here is my question: does anyone know whether the 383 manifold will flow air "slower" on the 440 block, than a stock 440 manifold? I am assuming the 383 manifold probably has narrower passages than a stock 440 manifold (can anyone confirm?). So that could mean either air flows faster due to the narrower passages & venturi effect.....or it could flow slower due to narrower passages. Or it might not make much of a difference at all.

I'm not building a high-performance engine, but if a stock 440 would perform a little better than a 383 manifold, I might make the switch.

Thanks much - Wade