B. Marine Mechanical Fuel Pump for 5.0, 5.7, 305, 350 Mercruiser and OMC For GM (Chevy) Marine 5.0 (305), 5.7 (350) engines Gasket included Replaces Mercruiser 861678A, 861678A1, 97401A2 Replaces OMC 509404 Please note position of inlet and outlet ports