As indicated earlier, our supercharger had been supplied with a 3.0", ten rib serpentine final drive pulley of which we had a number of concerns with. Most obvious is the serpentine drive. This would need replacement with a cogged set up. Further we required greater then a 1.2:1 overdrive, this necessitated a smaller dia. pulley at this location. As experienced at the front of the jack shaft, the bearing size and placement restrict decrease of the pulley diameter.