This product has been discontinued by the manufacturer and has been superseded by Mercury 43-803112T-1Sierra 18-2257 Mercruiser 1.65:1 Upper Gear KitSierra replacement Upper Gear Kit for Mercruiser Inline 6 Cylinder Engines with a 1.65:1 Gear Ratio. Ratio: 1.65:1; Driver Gear: 24 teeth; Driven Gear: 24 teeth; For: 6 cyl. inline engines; Kit Contains: (1) 18-1160 Drive Bearing Kit; (1) 18-1161 Tapered Roller Bearing; (1) 18-1165 Tapered Roller Bearing; (1) 18-2203 Upper Unit Gear Set; (1) 18-2619-1 Outdrive Gasket Set; (1) 18-2648 Upper Unit Seal Kit; (1) 18-2743 Outdrive Mounting Gasket; (1) 18-2820 Outdrive Gasket; Application:Mercruiser Stern Drive R/MR/Alpha One (Sterndrive); 1983-1991; s/n 6225577 thru 0D469858; R/MR/Alpha One (Transom Assembly); 1983-1991; s/n 6216687 thru 0D469858; Interchangeable with: GLM; 11225; Mercruiser Stern Drive; 43-803112T1;