car craft does say there is no advantage...in fact, they actually state that you get the advantage with aluminum heads of the light weight, which is why most race teams use obviously, and for other reasons as well...i think it was a great test, and it sheds light on the fact that there is really is no difference, other than weight...My buddy's 800hp chevelle makes the same amount of power with his ported iron heads as it does with the 3k brodix heads he put on...go figure, other than weight theres not advantage for him either