hi All, has anyone had much to do with barrel differences in the Yz250's? i have a 1999 2 stroke barrel in reasonable shape, but its collecting dust. i have a spare 2007 yz250 2 stroke that im rebuilding. i know the 1999 barrel will bolt straight to the 2007 case, but im wondering about porting/powervalve differences. can anyone shed any light for me? 1999 part number; 5CU-11311-02 2007 part number; 5UP-11311-20 i have access to a machine shop, so im considering boring the 1999 barrel out to 72mm and fitting a 71.96mm wiseco piston to make a yz300.