The Sierra 18-2171 Engine Coupler fits all GM model engines except MR/Alpha/Bravo with a "triangular" three-bolt coupler. It is interchangeable with the following: GLM 11500, Mallory 9-72502, Mercruiser 76850A2, 38965A1, 38965A2, 22492A2, 32492A3 and 32492A5. Each engine coupler meets or exceeds the original part it replaces. Fit specific, check part numbers before purchase to ensure proper fit.