Doesn anyone have any dyno time on the cast verse ALum head HP loss.

There was a chevy write up on Cast iron VS ALum head "same casting but different metals" and the difference was little to none.

I think the big difference in HP loss with ALum is when running the All Alum. engines and only in the big HP range to have any major drop in HP

found the write up

http://www.carcraft.com/techarticles/ccr...no_results.html