Interchange Part Numbe r: 18493. Heavy Duty 2.0kW, 3HP , OSGR, 12 Volt, CW, 9-TOOTH Pinion. for Chevy-V8 Small Block, Big Block& V6 with A/T& M/T with 153 or 168 Tooth Ring Gear 1955-2010. OEM(s) Replaced: for Chevrolet, Most of the Motors.