Sierra International 18-2909-9 Marine Exhaust Manifold Gasket - Pack of 2 Sierra Exhaust Manifold Gasket Meets or exceeds the original equipment quality Sierra part number: 18-2909-9 Interchangeable with the following: Barr MC47-27-99757, Crusader 97498, GLM 32170, Mallory 9-61421, Mercruiser 27-99757, OMC 915025, 3853412, Osco CS-GH, Volvo Penta 3853412, 856116, Yamaha YSC-12190-00-AC