if your just looking for a more down low power, i would just recomend an adjustable timing plate, maybe a coolhead with small domes, low end pipes like pro circuit or FMF's or something like that. maybe u could just change ur gearing. if u wanna spend alot u could just get a trail port and/or stroker crank and shit. all depends on how much money you want to spend. i would say these would be cheaper and less of a PITA than a RZ topend with PV's.