Used 13.9mm-25 tooth blower pulley. This pulley is 3.50" wide and has a 2.00" register made from billet aluminum with six .375" bolt holes on a 2.782" bolt circle. Fits 4-71 thru 18-71 roots superchargers.
Pulley has one offset hole for early type crank hubs that have one offset mounting hole but pulley can be used on crank hubs with all six bolt holes that use equal bolt spacing with no issues.
Teeth show a little wear but lots of passes left on this pulley.