Sierra 18-0389 MerCruiser Heat Exchanger End GasketSierra high-quality engine parts are designed to meet OEM specifications.Features: Fits: 3.7L w/ 4 inch heat exchanger.; Diameter: 3-15/16"; Interchangeable with: GLM; 31830; MerCruiser Stern Drive; 27-99960; Application:MerCruiser Stern Drive 165 2 BBL Mercury; 1985-1987; 0B434941 thru 0B774251; 170 2 BBL Mercury; 1985-1986; 6916779 thru 0B434940; 180 4 BBL Mercury; 1987; 0B436391 thru 0B775248; 190 4 BBL Mercury; 1985-1986; 6916779 thru 0B436390; 3.7L 2 BBL Mercury; 1988-1989; 0B774252 & up; 3.7LX 4 BBL Mercury; 1988-1989; 0B775249 & up; 470 2 BBL I/L4; 1982; 5520115 thru 6218036; 470 2 BBL Mercury; 1983-1984; 6218037 thru 6916778; 470 2 BBL I/L4; 1980-1981; 5520115 thru 6218036; 470 MIE 224 I/L4; 1980-1981; 5520115 thru 6218036; 485 2 BBL 224 I/L4; 1980-1982; 5685394 thru 6218036; 488 4 BBL Mercury; 1983-1983; 6170297 thru 6916778; 488 4 BBL 224 I/L4; 1984-1984; 6170297 thru 6916778;