318 advice

I guess it really depends on how much your going to street drive the engine, if it's going to be mostly street and some race then the 302's would be best. But if you plan on running different pistons and more race then the head isn't as much a factor, because the quench distance can be achieved either way. Both the 302's and the eariler heads can be made to flow the same. So port volumes and flow's are similar.