Crankshaft Turning Socket Chevy Big Block Fits Small Big Block Chevy Engines, 1965-1992 models This non-marring, aluminum tool rotates the crankshaft the proper way, when the balancer is off Fits 1.610 ID Crankshaft Snout with 3/16 Inch Keyway 1/2 Inch Drive for Use with Breaker Bar or Drive Ratchet