Billet Aluminum Ford FE Engine Crankshaft Pulley for 390, 427 & 428 FE engines. Pulley provides 87% underdrive ratio when used with CVF Racing water pump pulley. Designed for use with stock power steering and alternator brackets. Fits engines without casted V-Groove in dampener. 3 Bolt pattern on crankshaft pulley and dampener face to water pump flange face is 2 3/8”. Pulley Diameter is 6.2" with 5/8" pilot diameter.