Pulley uses six .375" bolts on a 2.782" bolt circle with a female/male 2.00" register which is industry standard with most blower drive applications. Pulley is 5.750" in diameter, 2.310" thick and is designed to cup back over the crank hub on the engine.
Buyer must know if there engine is from car or truck when purchasing to get the right acc. pulley. Pulley is designed to be used with #2300-0010C crank hub and is not set up to be used with factory harmonic dampener.