Oldsmobile Blower crank hub. these are brand new. 303-324-371 cubic inch engines with 1.500” crank snout 4140 steel Heat treated to 46RC 2” blower pulley register Uses Six-.375” bolt circle on a 2.782” bolt circle. .250” keyway When using a stock timing cover you will need to replace seal with a larger ID to accommodate the extra width in the hub. American made in Paso Robles, Ca. $200.00 + 20..00 s/h PayPal or USPS money order preferred. Please, PM me with any questions