Aluminum Heads ?
Street Demon, am I understanding correctly that in your first post the 2-4 hp difference went back & forth between the 2 types of heads depending on the RPM?
I guess the main thing I'm trying to find out is if an IDENTICAL Iron head would make more power than an aluminum head because of the heat loss from the aluminum head. Same cam, combustion chamber, ports, etc. I'm wondering if the bump in compression ratio will increase the power the same amount between an aluminum head & a cast iron one. If I understand street demon's post, the head material itself will have little effect on the power produced, but the increase in compression ratio allowed by the aluminum head will let you make more power than the iron head would when operating on the edge of the compression that is allowed by the octane of the gas.