Originally Posted by sel2real
other than a weight savings, there isnt much more that aluminum heads offer over the cast irons. the biggest problem with fe's is the angle at which the intake fuel/air mixture has to turn to get into the combustion chamber. without a total redesign of the intake and cylinder heads, there isnt much power to be seen with any aftermarket head. aluminum weighs less than iron though, and considering the "bling" factor.... taking measurements of the port sizes in the stock iron heads will probably also amaze you. you'll find out that the factory ports are already large - probably more than they need to be being stock.
Your kidding right? I can't think of a worse head on the flow bench than a Ford FE. I can't think of a worse performing big block motor from the 60's and 1970 than a 390. I know, I drove one.
An aftermarket cylinder head will gain you more on the bottom, mid and top. About the best mod I can think of for a big block Ford.
How do I know? Had more than a few big block fords on the dyno.