Your going to gain about 50 cfm of flow on the intake and the exhaust on an aftermarket head versus a stock 390 FE. Granted even +50 on a head that flows 200I and 130E is still quite poor even compared to a stock small block chevy of the time.
My statement was take the stock heads off and bolt on a set of aftermarket heads. You'll make more power low mid and high. Much better than a stroker with a stock set of heads. Nothing was ever said about ported heads versus stock aftermarket heads. In stock form the FE head is as poor a flowing head as you can find.
I guess I can't even fathom a balls to the walls motor with stock casting Ford heads. If we build a balls to the walls BBF Ford motor it had BETTER spin out 900+ on the dyno for a motor that can be run on the street but mainly for track use. A track only balls to the walls BBF race motor better do 1200 to the wheels.
I'm not arguing or bashin but in our shop if a pair of cylinder heads for a BBF balls to the walls motor aint flowing 400 CFM range, it aint balls to the walls in our book.
Just my opinion.