I finally did some work to a set a few months ago, and without comparing before and after dyno #'s it's tough to say if the work I did indeed helped, but we beat our goal on a pump gas 408 making 550HP with a hyd roller cam...we made 567. I'm doing another build just like it with a couple of different tweaks to make an honest 575HP with hyd roller cam and under 11:1 compression.