Sierra 18-3329 Grommet The Sierra 18-3329 Grommet is interchangeable with the following: GLM 86492, Evinrude/Johnson 302497, Mallory 9-43603. Each Sierra product meets or exceeds the original equipment part it replaces. Sierra Grommet Meets or exceeds the original equipment quality Sierra part number: 18-3329 Interchangeable with the following: GLM 86492, Evinrude/Johnson 302497, Mallory 9-43603