the o.s. speed is an outstanding motor to say the least.....You will not be disapointed with the out of the box performance.. easy to tune and has tons of power.. I have the o.s. vzb aswell (blue head) modded by mark of powerhouse mods and it screams ... I have them both set up with the max life dyn. alum shoes, 13t racers edge vented cb with the ttr 2035 pipe...