true reason i wont do build build on my 318 it numbers match block in my 79 powerwagon i wont use 302 heads and my 69 340 square bore intake port heads to match intake run 68 spec 340 cam just try find right pistons to run in my set up heard lot bad things about Hypereutectic and coated piston skirts im going use molly rings wont to bring compression up to 9s and ideas would be great will not be use stock tin head gaskets