These Power Pulley Packs for 1986-1993 Ford Mustang 5.0L feature lightweight, aluminum 6.87" Crank / 4.75" Accessory drive Pulley and your choice of supercharger pulley, a heavy-duty dual bearing idler, supercharger belt, and all appropriate hardware including idler spacers. Our pulleys offer unique features such as proper SAE specification contours machined directly onto the drive surface of the pulley, which greatly extends the life of the belt.