Optimum setup for 302 heads
But you only have 318 CI to work with, so the bigger is better thing doesn't apply here.
All my information that I use for figureing out how much head go's on a given engine is:
Piston speed
bore
stroke
rod to stroke ratio
bore to stroke ratio
Intake manifold size and port shape
exhaust diameter and length
camshaft design
so when all this info is gathered and put together I can now figure out the cc's of the runner and how much air it needs to flow and the size of the valve that will work the best.
Then the head choice is made.