I am looking at an EFI conversion on my BBC. This is a used FAST system. It was removed from a 502 crate motor being run in a P/U. The owner wanted to switch back to a carburetor. The manifold is an oval port design (so like for like with my set up) converted over to injectors. My question is the difference between my 454 Mark IV and the 502 Mark V or VI block as far as intake manifold fit. Besides the changes in the block to one piece main seals, mechanical fuel pump casting deletes and lack of manual clutch linkage bolting areas, were there any changes to the valley dimensions? Can I bolt the Mark V or VI intake manifold to the Mark IV block. I do not think there are any differences between head design and the manifold to head surfaces? The internet searching I have done seems to show everything will fit. Any thoughts or information? Thanks, Rhys.
Some Mark V blocks do have the boss for the clutch linkage and all also have a deck vent hole which has to be blocked off if using early heads. The Mark V1 has the fuel pump boss as well as the clutch linkage boss. The vent hole in the deck is also gone. I believe intakes interchange but you may have to 'port match' Please correct me if I'm wrong.