Time for the Machine Shop!

I think maybe is you were planning to upgrade the heads, find a set of 302 castings and have them redone instead might be better. BTW, the 268 cam takes no special head prep. Just single springs with dampners and he should set the heights correctly as part of the valve job. I wouldnt waste $$ porting the '74 318 head. Just me tho. I priced new Engine Quest Magnums with the LA intake pattern for a build I'm thinking of doing. $320 a head plus shipping for a much better head with new guides and seats, and modern smaller chambers...