• Small Block Chevy Black Crankshaft Lower Pulley
• Black Pulley.
• Fits Small Block Chevy 283-350 Engine.
• Fits 1969-85 Long Water Pump.
• Triple Groove.
• 6.60 Diameter with 2.30 Bolt Circle.

To determine if your water pump is short or long.
If your alternator is originally on the driver's side then it is a short water pump.
If your alternator is orginally on the passenger's side then it is a long waterpump.
If you can fit your hand between the waterpump and the timing chain cover then you have a long waterpump.