The Sierra 18-2191 Carrier Bearing is interchangeable with the following: GLM 11405, Mallory 9-72601, Mercruiser 73020A14, 56211A1 and 73020A1. Each Sierra product meets or exceeds the original equipment part it replaces. For: Housings with casting #73020C. Fits: MC-I, R, MR & Alpha One.