*** IN STOCK SHIPS TODAY *** 392/417 Hemi 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 4-71 thru 16-71 roots or screw superchargers. This hub is for all internal balance Gen 1 Hemi engines including 354, 392, 417 and many more. Hub measures from pulley mounting surface to crank gear 2.220".