I have a 70 318 that many years ago I put a set of 360 heads on and bolted on a stock 360 4 bbl spreadbore manifold. Now I know that this configuration has a huge problem primarily because the combustion chambers are huge and will lower the compression ratio to pretty near 7:1. Now while it runs ok and will not "ping" even on the trashy gas I know I can do better. So Im thinking about getting a set of "302" swirl port heads and going with an aftermarket 4bbl manifold. My question is what will fit and not cause any fuel turbulence or reversion problems between the new intake and the '302" head intake port?