[fiveohpatrol]

Where does this 8 tenths faster from unported gt40 irons come from? 9
Theres no way a car will pickup that much time with JUST the addition of the GT40's. Maybe 9-9 tenths if you go from stock heads/cam/intake to PORTED GT40s with an aftermarket cam and intake, but no way with just the heads.

Yes stock GT40's are better than highly ported E7s, but not much. I had a chance to look at a set off of a 95cobra and the ports on them weren't any bigger than after I was done porting mine. The valves are bigger though.