no i mean how many miles are on ur engine?...as long as ur milage isnt too high..and ur motor is runing good and all u will be ok with boosting to a certian point..im not to sure about a DOHC but i know on SOHC u can boost like around 6 lbs maybe a little more no problem on stock internals...im new to the DOHC game so someone here will have better info on how much boost and whatnot