55-72 Small Block Single Groove Crankshaft Pulley without AC, (6-3/4" Diameter). Stamped 3755820-BC GM
GM Group #: 0.659
GM Part #: 3755820 Important Warning Concerning Crankshaft Pulleys: Stock replacement pulleys are not designed to exceed 400 horsepower or 6,000 RPM. Using reproduction pulleys on engines in excess of these limits may result in catastrophic disintegration of the pulley causing severe damage to the engine, cooling system and body. Classic Headquarters assumes no liability for damages caused by improper usage of pulleys. Please be sure to install the pulley properly to avoid damages that could occur from improper installation or exceeding recommended RPM limitations.