*** IN STOCK SHIPS TODAY *** SBF crank hub made from billet heat treated steel, has two .250" keyways 180 degree's apart. Uses six .375 bolts on a 2.782" bolt circle and is made to work with 6-71 thru 16-71 roots or screw superchargers.
This hub is for all internal balance small block Ford engines including 289, 302, 351 and many more. Hub measures from pulley mounting surface to crank gear 2.975".