Fitment: fit any SB Chevy Engine when using a LONG water pump SB Chevy 265 283 305 327 350 383 400 V8 Engines Water Pump Pulley: Double Grooves Pulley Diameter is 6 9/16" Pulley is 3" Tall Bolt Pattern is 2 1/8" Center hole is 5/8" Belt Type: V-Belt Machined From Billet Aluminium These Feature deep grooves to prevent belt from slipping Crankshaft Pulley: .