Billet Aluminum Pontiac Crankshaft Pulley (1968+) 2 Groove Crankshaft Pulley for Pontiac Engines (350 - 400, 428 & 455). Designed for use with stock power steering and alternator brackets. FITS VEHICLES WITH: 1968 or newer dampener 1969 or newer water pump (4.5" from flange to engine block) PONTIAC V8 ENGINES (350 - 400, 428 & 455) 1968+ Pontiac Passenger Cars Generally fits the following models with original 350, 400, 428 & 455 engines installed. Note: 1968-1969 were transition years and you need to ensure that you have the correct water pump and damper. 1968 - 1974 Pontiac GTO 1968 - 1977 Pontiac Grand Prix 1968 - 1981 Pontiac LeMans 1968 - 1976 Pontiac Bonneville 1968 - 1976 Pontiac Firebird 1968 - 1976 Pontiac Transam 1968 - 1981 Pontiac Catalina 1978 - 1980 Pontiac Grand Am 1968 - 1972 Pontiac Tempest 1968 - 1977 Pontiac Ventura This is not a complete list. If you have a question about application, please e-mail us. It is not recommended that you select pulleys solely based on model and year alone because often the original engine has been swapped. Diameter: 6.2" Overall Length: 2.0" Grooves: 2 Bolt Pattern: 4 Bolt Bolt Circle: 3.75" Pilot Diameter: 2.5"