You know Dan, the first engine I built was a 318 with 360 heads. We didn’t mill the crap out of them either.
Strip Dominator. Hooker 5204 headers. And a 284/484 cam.
And you know what? He took money from a lot of fools who underestimated that little 318.
I do not know what math you are using or what experience you have but it clearly is wrong.
That engine didn’t need rpm to make power. The idea that ANY production cylinder head is too big for a 318 is silly and wrong.
These things are under valved and under headed severely. You can’t hurt a 318 with a W2 head. And you don’t have to spin the engine to the moon.
This idea you can get the heads too big on one of these engines is nonsense.