have the block chamfered, that what we have done on 283 engines. I always bolt my heads on the block like that and check them, even more so if your sending the heads out for porting - i will mark the cylinder on the deck so the porter can see where the head will be sitting
Unfortunately in the CFM wars a large combustion chamber is a requirement to get the big flow numbers. I believe that the bulk of the heads being built are designed on the 400 bore size to achieve these flow numbers, but it isn't uncommon, just do the same inspection on a big block Chev and you will see even more bore overhang.
Use the correct head gasket, and bolt them on and go.
It appears the intake valve still clears the bore's edge rather easily. The smallblock valves travel in a straight line so you shouldn't have any huge problems with them hitting the block, so what's the problem? A BBC intake valve is much closer to the edge and has a relief in the block to help clear everything.
A forum community dedicated to Chevrolet Chevelle owners and enthusiasts. Come join the discussion about restorations, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!