Quote Originally Posted by jman44 View Post
I have a 99 gp gtp coupe. has speed daddy headers, no cat, magna flow mufflers, roller rockers. My question is what can i safely drop to on my s/c and run kr free?
I'd guess you can go with a 3.4 without KR but like the others mentioned a scan gauge would be smart. I'm assuming you have an intake also right? I'm running a 3.3 with similar mods except for a mild cam and a little bowl porting on the heads. I have an Aeroforce and have not shown any KR. I've got a 3.2 on the way and will keep an eye out for knock.