Small Block Chevy Black Aluminum Water Crank Pulley Set 1 / 2 Groove LWP SBC 350. This is a brand new Small Block Chevy Aluminum Pulley Kit. The Water Pump Pulley is. The Crankshaft Pulley is. They are constructed of thick gauge aluminum and with a high quality Satin Aluminum finish. Finally this kit also includes the aluminum alternator pulley with aluminum fan. This set is designed for most original GM alternators as well as aftermarket 1 or 3 wire alternators. The pulley diameter is 2 13/16 and comes complete with a dress up nose cover. A nice finishing touch to upgrade an old or new alternator. 5- Single Groove Water Pump Pulley(with bolts). Double Groove Crank Pulley. Single Groove Aluminum Alternator Pulley With Nut Cover. Aluminum Alternator Fan Blade. P Professional Installation is Highly Recommended (No Instruction and Wiring Diagram Included).