Well I will say they are or seem to be somewhat nitrous friendly from what I have seen. Also they have some issue, biggest being the valve angle and of course lack of bore on a Mopar. You can make power with them. more than any other Mopar head for sure. But it comes at a cost for sure. Mine made decent power and once we get some stuff straightened out, cam, intake mainly wer feel there is another 70ish in it. But for now it is what we call a Beat deal...