Sierra 18-2201 Upper Unit Gear Set

Replaces OEM part #MERCURY MARINE 43-18410A2MERCURY MARINE 43-18411A2For: Most Mercruiser V-8 Drives and Gen II(S/N OK999999 & Below) with 1.5:1 Gear Ratio(Drive Gear = 22 teeth; Driven Gear = 20 teeth). Also fits Mercruiser stern drive models: 225 (S/N 3856268 - 4200499); 260 (S/N 4898730 - 6225576); 898/228 (S/N 4782330 - 6225576); 888 (S/N 3106717 & UP); V8/MR/Alpha One (S/N 6225577 & UP).Kit Includes: (1) 18-1142 Upper Pinion Bearing - replaces O.E. # 31-32573A1