Indy 360-1 vs Edelbrock RPM heads

273 said
My point was they only rated the stock Edelbrock head for 417 hp, (1.61 hp per cfm)

I think you misunderstand. If “They” is Edelbrock. The head is not rated for that level but the power package is.

273 said
I find most builds we see fall short of the 2hp per cfm, 1.7-1.9 hp per cfm for 230-250 ish cammed engines.

Oh yeah! But then again, no one is trying for it.