The pulley has a register on the back that fits in the dampner as well as a 2.00" male register on the front to keep your supercharger pulley running concentric. Included is grade eight mounting hardware and pulley O.D. is 6.00" in diameter. This pulley uses six 3/8" bolt holes on a 2.782" bolt circle for mounting of supercharger pulley.
Fits 4-71 thru 16-71 roots or PSI screw superchargers.