Indy 360-1 vs Edelbrock RPM heads

This is a good example of comparing apple to apples.... what was the estimate cost difference between both??

On the Indy 360-1, i know the intake and head internals will have to be different compare to i.e if I decide to use Edelbrocks, sinceI was running Pro comps'........
But, what about my existing headers? Are the Indy's 360-1 going to fit using my existing 1 7/8 ( LA type square ) headers?
I'm running the same Hedman headers on my Indy 360-1's that I ran on my Edelbrocks.