Description Cylinder Sleeve: Mercury / Mariner 135 - 175 Hp Mariner ALL Mercury 6 Cyl 3.125 Bore 2L 135 1986-2000 Mercury 6 Cyl 3.125 Bore 2L 150 1978-1998 Mercury 6 Cyl 3.125 Bore 2L 175 1976-1981 Mercury 6 Cyl 3.125 Bore 2L XR2 150 1986-1988 Note: 3.3125"