Sterndrive Engineering Repl Lower Unit Merc R,Mr,Alpha One
Sterndrive Engineering Repl Lower Unit Merc R,Mr,Alpha One, Sterndrive Engineering Replacement Lower Unit Mercruiser R, MR, and Alpha One90-106-02 Replaces R, MR, Alpha One lowers from 1972-1990; 13 Spline Driveshaft; Tooth count is 13-21; Up to 300 HP; 90-108-02 To replace Counter Rotation units only; Item is subject to a 20% restocking fee (Boat Covers, Bimini Tops, Outdrives, Drop Ship Items and Special Order Parts)!**Year, Serial Number, and Horsepower are required to order. Please contact us with this information after you place your order otherwise processing will be delayed.Sterndrive Engineering Model ChartRefer to Sterndrive Engineering's model chart below to find your proper Mercruiser Sterndrive Replacement. These are typical applications; it is best to confirm your ratio by couting the teeth in the upper. Although great care was taken in the creation of this guide, its accuracy cannot be guaranteed. Model Year Range Serial Range Notes (See Below) Standard Rotation Counter Rotation 120,140 1967-1969 2062141-2791956 1,2,3,4,5,6 1.94 1.94 CR 120,140 1970-1982 2791957-6225576 2,4,5,6 1.94 1.94 CR 160 1967-1969 2065190-2763441 1,2,3,4,5,6 1.62 1.62 CR 165 1970-1977 2763442 and up 2,4,5,6 1.62 1.62 CR 225-S 1974 3856268-4200499 4,5,6 1.47 1.47 CR 233 1975-1977 4200500 4,5,6 1.47 1.47 CR 250 1977 4791300-4898729 4,5,6 1.47 1.47 CR 260 1978-1982 4898730-6225576 4,5,6 1.47 1.47 CR 470 1976-1982 4208730-6225576 2,4,5,6 1.81 1.81 CR 485 1980-1982 4893835 and up 2,4,5,6 1.81 1.81 CR 888 1971-1977 3106717 and up 4,5,6 1.47 1.47 CR 898/228 1977-1982 4782330-622576 4,5,6 1.47 1.47 CR R/MR/Alpha One 1983-1990 6225577-OD469585 6,7 Notes: Unit has an 8 spline driveshaft on the lower unit. If your unit is original, you need to purchase a complete.; Unit has a short yoke on the upper driveshaft. We refer to this as the "Old Style"; ***Applies to all inline 4 and inline six cylinder engines up until and including 1982***; Unit must have trim and tilt for our Replacement to work. If it has two trim hoses going to each cylinder, it has trim and tilt.; Unit has an eyelet on top cover. Replacement unit will not.; Unit has a round cavitation plate on lower unit. Replacement unit will not.; Unit may have an o-ring and/or a preload pin on lower unit driveshaft. The replacement will not.; Gear Ratio must be confirmed. Chart below is typical applications, however there is no guarantee it is correct. To be safe it is best to remove the top cover and count the teeth on the upper gears.; Engine Configuration Horsepower Gear Ratio Tooth Count Standard Rotation Counter Rotation Inline 4 Cyl. 2.5L/3.0L 120,140 1.98/1.94 20/24 1.94 1.94 CR Inline 4 Cyl. 3.7L 170 1.84/1.81 17/19 1.81 1.81 CR Inline 6 Cyl. 160/165 1.65/1.62 24/24 1.62 1.62 CR V6 4.3L 185/190 1.84/1.81 17/19 1.81 1.81 CR V8 305 2 Barrel Carb. 200 1.65/1.62 24/24 1.62 1.62 CR V8 305/350 230/260 1.50/1.47 20/22 1.47 1.47 CR