Designed and recommended for usage with stock engines to lessen rotating mass, reduce fat, also to enhance power transfer from engine without energy loss. Using the Slipper Eliminator, engine performance is relocated directly to the auto, and there is also no reliance on clutch & slipper modification. Dealing the spur gear is very really fast & effortless. Slipper Eliminator is an instantaneous replacement the slipper clutch set. Appropriate LCG gearboxes. Fits simply and fast top shaft 324116. Set includes aluminum spur gear hub, and 72T spur gear (an optional 69T spur gear is had).