Made by Scott Drake from the original factory print. This pulley is the same as Drake's reproduction HiPo pulley used on 289 HiPos, some Boss 302/429 cars and 429 Cobra Jets right down to the part number stamped on the face. Except for one thing, it's in a custom chrome finish never offered by the factory. This 3.78" O.D. pulley is larger than standard engines used in order to slow down the alternator speed on high revving performance engines. It will physically fit virtually any 1965-1973 alternator as an underdrive pulley but you will need the correct length belt!