Alpha One® Gen I Sterndrive Complete - 1972-1990 | SEI SE106

Sterndrive Engineering

$1,755.00
Unit price per

Sterndrive Engineering Alpha One® Gen I Sterndrive Complete Replacement Sterndrive(Replaces Mercruiser's Alpha One) | SE106

Alpha One® Gen I Sterndrive Complete
Replaces most Mercruiser Sterndrives 228 HP and up from 1972-1990.
Ships in two boxes. Comes with a 9-9/16 new style input yoke.
Does not include Complete Install Kit or Anode Kit. Please see related items below.
Up to 300 HP (SEI does not warranty applications over 300 HP)
Replaces Mercruiser Sterndrive 225-S 1974, Replaces Mercruiser Sterndrive 233 1975-1977, Replaces Mercruiser Sterndrive 250 1977, Replaces Mercruiser Sterndrive 260 1978-1982, Replaces Mercruiser Sterndrive 898/228 1977-1982, Replaces Mercruiser Sterndrive R/MR/Alpha One 1983-1990
Typical Mercruiser Sterndrive engine liter applications from 1983-1990 include 5.7L, 5.0L (4 barrel carb) | Typical Mercruiser Sterndrive engine cubic inch applications from 1983-1990 include 350, 305 (4 barrel carb) | Typical Mercruiser Sterndrive engine horsepower applications include 260, 230, 228

Additional Information

Replacesmost Mercruiser Sterndrives from 120 -260 HP 1967-1990
YourMercruiser Sterndrive must have trim and tilt to be able to use our replacement drive.
Ifyour Mercruiser Sterndrive is between 1967-1969 you must verify that you have 13 splines on your upper driveshaft .
Shipsin two boxes. Comes with 9 -9/16 input yoke.
Doesnot include Complete Install Kit or Anode Kit. Please see related items below.
Todetermine if you have a counter rotation unit on your twin engine boat it is easiest to look at the props.

If the props are identical orientation, then they are both standards. If the prop blades are opposite, then the port should be a counter rotation

Pleaserefer to the model chart below to find your proper Mercruiser Sterndrive Replacement.

These are typical applications, it is best to confirm your ratio by counting the teeth in the upper. Although great care was taken in the creation of this guide, SEI cannot guarantee its accuracy.

Model	Year Range	Serial Range	Notes See Below	Complete Std. Rotation	Upper All	Lower Std. Rotation	Complete Counter Rotation	Lower Counter Rotation
120/140	1967-1969	2062141-2791956	1,2,3,4,5,6	1.94	See #1	See #1	1.94 C.R.	See #1
120/140	1970-1982	2791957-6225576	2,4,5,6	1.94	1.94	Lower	1.94 C.R.	Lower C.R.
160	1967-1969	2065190-2763441	1,2,3,4,5,6	1.62	See #1	See #1	1.62 C.R.	See #1
165	1970-1977	2763442 and up	2,4,5,6	1.62	1.62	Lower	1.62 C.R.	Lower C.R.
225 -S	1974	3856268-4200499	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
233	1975-1977	4200500	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
250	1977	4791300-4898729	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
260	1978-1982	4898730-6225576	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
470	1976-1982	4208730-6225576	2,4,5,6	1.81	1.81	Lower	1.81 C.R.	Lower C.R.
485	1980-1982	4893835 and up	2,4,5,6	1.81	1.81	Lower	1.81 C.R.	Lower C.R.
888	1971-1977	3106717 and up	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
898/228	1977-1982	4782330-622576	4,5,6	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
R/MR/Alpha One	1983-1990	6225577-OD469858	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.
GearRatio 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	Complete Std. Rotation	Upper All	Lower Std. Rotation	Complete Counter Rotation	Lower Counter Rotation
Inline 4 Cyl. 2.5L/3.0L	120/140	1.98/1.94	20/24	1.94	1.94	Lower	1.94 C.R.	Lower C.R.
Inline 4 Cyl. 3.7L	170	1.84/1.81	17/19	1.81	1.81	Lower	1.81 C.R.	Lower C.R.
Inline 6 cyl	160/165	1.65/1.62	24/24	1.62	1.62	Lower	1.62 C.R.	Lower C.R.
V6 4.3L	185/190	1.84/1.81	17/19	1.81	1.81	Lower	1.81 C.R.	Lower C.R.
V8 305 2 Barrel Carb.	200	1.65/1.62	24/24	1.62	1.62	Lower	1.62 C.R.	Lower C.R.
V8 305/350	230/260	1.50/1.47	20/22	1.47	1.47	Lower	1.47 C.R.	Lower C.R.
V8 454 7.4L	330	1.32/1.29	20/16

*Gear ratio not available. You could substitute a 1.47 ratio, but it would not be covered

under our 3 year warranty as it is over our 300 HP Limit

Brunswick Corporation is the Original Equipment Manufacturer (OEM). Sterndrive Engineering, Inc. (or SEI) has no affiliation with the Brunswick Corporation. Sterndrive Engineering, Inc. manufactures a stern drive designed to replace Mercury Marines MerCruiser, Alpha One, R, MR, and Gen II stern drives. MerCruiser, Alpha One, Gen II, R, and MR are trademarks of the Brunswick Corporation. As with any after-market product, any warranties governing products manufactured and/or sold by Brunswick Corporation will not apply to products manufactured and/or sold by Sterndrive Engineering, Inc. (or SEI) or to products damaged due to the operation of an SEI product.