i have yet to pull heads to check port height of this xr6, anyone know? motor runs well but just doesnt pull the rpm's i've been told it should? i've been told it will never turn up due to porting, yet there's people on here that have proven that theory wrong. am i wasting my time with in in stock form? i'm running a 260 tuner, wh46's and wmh32's, stk 40amp flywheel. any advice would be appreciated! sean