Cams choice, Low CR vs VE%

Let me see if I’m following here.

If I’m building a 318 and I need heads do I chose a 318 head and keep the CR up or a 360 casting and get the flow?

Every single time I pick the 360 head. All engines are a series of compromises. The engine with the least amount of compromises is always better.

That’s why I pull my hair out when I see guys building 400 plus inches and use a stock casting or even an Edelbrock head. That is so induction limited that to get any reasonable RPM out of it you have a cam that is the dread bottom end killer.

But that torque number is up there.

That’s if I’m following your thinking.
Always a dilemma and a topic of discussion. A early 273/318 head ported would be the closest you could come to the best of both worlds. Edelbrock aluminum's or the like would be a good choice as well. Small efficient chamber, compression, and port flow. But you know that already.