Can't remember...its something stupid like .570/.566 give or take .005/.010...but its nuts. If you really want it the other buyers backed out. SO your on the top of the list. Let me know if your still interested. You'll be able to run a pretty small pulley for a high compression build too. Nick (Bio248) said he was running a 3.4" with headers and this cam with NO other mods but a hogged out throttle body/blower and a cold air intake with no knock at all. Said he could have prolly dropped it to a 3.2" with bigger injectors and a custom tune.