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