Originally Posted by sc4405

I'm going through this same scenario w/ a 598 right now, just won't run the MPH that it should. Biggest problem is the heads, mine has BB2Xtras CNC on it and they just won't support an engine of this CI. I'm agonizing over the Headhunters or the 3Xtra CNC right now. HH's will require new shaft rockers, intake and maybe pistons. I'm running nearly the same cam as you, and all the builders I have talked to said it's too big for the heads, but would work with better heads. You should pick up some w/ better headers, but it's still choked off with the heads. I don't have the coin for the headhunters right now but who knows later on............good luck to you! 8) JB