(1) New High Quality OEM Spec Mercury Aftermarket Replacement Upper Box Gearcase Seal Kit. Fits The Following Mercury Models: 1963 - 1963 Model / HP 1 ~ Serial# 1534570 - 1684187, 1964 - 1966 Model / HP 1A, 1B, 1C & EZ Shift ~ Serial# 1684188 - 2065189, 1967 - 1982 Model / HP 120 / 140 ~ Serial # 2062141 - 6225576, 1976 - 1982 Model / HP 470 / 485 ~ Serial # 4208730 - 6225576, 1967 - 1977 Model / HP 160 / 165 ~ Serial # 2065190 and Up, 1971 - 1977 Model / HP 888 ~ Serial # 3106717 and Up, 1974 - 1977 Model / HP 225 / 233 ~ Serial # 3856268 and Up, 1977 - 1982 Model / HP 898 / 228 / 250 / 260 ~ Serial # 4782330 - 4898729, 1983 - 1991 Model / HP R / MR / Alpha One ~ Serial # 6225577 and Up, and 1986 - 1989 Model / HP Alpha One SS ~ Serial # 0A 545004 and Up. It will fit the R, MR and Alpha One Upper Gear Housings from 1991 and earlier. For #1 and Alpha One TO 1997. Upper Gear Housing Seal Kit for all Mercruiser #1, MR and Alpha 1 (One) drives from 1964 thru 1991 (Serial Numbers 1684188 thru D469858). Replaces Mercury OEM Part Number: 26-32511A1. Also Replaces Sierra Part Number: 18-2648. MERCRUISER ALPHA ONE UPPER BOX GEAR CASE SEAL KIT 87500 is a Subset of these Product(s): 11215 - UPPER GEAR SERVICE KIT, 11225 - UPPER GEAR SERVICE KIT, 11235 - UPPER GEAR SERVICE KIT, 11245 - UPPER GEAR SERVICE KIT, 28313 - MERCRUISER ALPHA ONE YOKE & U-JOINT SERVICE KIT, 28314 - MERCRUISER ALPHA ONE YOKE & U-JOINT SERVICE KIT, 88010 - WATER PUMP & SEALS SERVICE KIT.