Complete Upper Gear Case

Replaces: Mercruiser: 12-815952, 815952

Engines: ALPHA ONE GEN II (1991+)

Replaces: Mercruiser: 1623-8951A43, 5-5010147CP, 623-8951A43, 8951A43, Sierra: 18-2443

OEM: 1623-8951A43

Engines: 6225577  + (1972-92)

Gear Teeth: 13/21

Splines: 13

OEM: 1623-8951A43

Replaces: 1547-9412A23

Ratio: 1.98/1.94 (20/24)

Engine: 4 Cylinders Inline

Replaces: 1547-861063A12

For: Alpha Gen II (1991 & UP) for gear ratios 1.47:1, 1.50:1.(20/22)

Engine: 5.0LEFI/5.7/350 MAG

Replaces: 1547-9412A22

Ratio: 1.84/1.81 (17/19)

Engine: V6 & 470/485

Replaces: 1623-815822A36, 1623-815822A30

For: Ratios 1.47, 1.62

Gen II (1998 & up), (0L100040 & up)

serial number: OD469859 - OK999999

Replaces:

Mercruiser: 1547-9412A20, 5-5010147CP, 547-9412A20, 547-9412R20, 8265A15, 9412A30, 9412A35; Sierra: 18-2450

Engine: up 300 HP - most V8

Ratio: 1.47 (20/22)

Replaces: 1623-8951A27, 1623-8951A37

For: MR/ALPHA Style

Bore size 3.2635-3.2650. Includes tapered roller bearing for non-tractor 14/28 or 17/28 gears.

Replaces: Mercruiser: 26-32511A1, 27-94996A3, 27-94996Q2, 27-94996T2, 64818A3, 94996A2, 94996A20, 94996BK2, 94996Q2; OMC/Johnson/Evinrude: 0508537, 0508539, 0508557, 0508577, 0775545 

Alpha One Gen OD469859-OK999999 (1991 - 97)

Replaces: 1547-861063A10

For: Alpha Gen II (1991 & UP) for gear ratios 1.62:1, 1.65:1, 2.0:1. (24/24)

Engine: 4.3LH/4.3LEFI/5.0L

Replaces: 1547-861063A8

For: Gen II (1991 & UP) for gear ratios 1.81:1, 1.84:1. (17/19)

Engine: 4.3L/4.3LX

# OD469859-OK999999, 1991-1997

Replaces: 1547-815930A7

Replaces: 1547-9412A21

Ratio: 1.65:1/1.62:1 (24/24)

Engine: 6 Cylinders inline

Replaces: Mercruiser: 74639, 74639A2, 74639B1, 74639Q02; Bombardier: 0508696, 0775542

Replaces: 1623-815822A53

For: Ratios 1.47, 1.62, 1.81 & 1.94

Fits: Gen II (1998 & up) 0L 100040 & up

Serial number: OD469859 and up.

Serial no. 6225577 & up

Replaces: 1623-8951A26, 1623-8951A33