This SEI Marine Upper Gear Set is a direct replacement for Mercruiser 5.0L V8 sterndrives featuring a 1.62:1 gear ratio.
It fits Type I, R, MR, and Alpha I drives from 1973 through 1990, including early models prior to the Alpha Gen II design.
Precision-machined for smooth operation and long-lasting performance, this gear set replaces OEM part number 43-45814A5 and restores proper drive ratio and torque output for reliable marine performance.
Manufactured to OEM standards for strength, noise reduction, and fitment accuracy.
Product Features
- Manufacturer: SEI Marine
- Application: Mercruiser I, R, MR, and Alpha I (1973–1990)
- Engine Compatibility: 5.0L V8
- Gear Ratio: 1.62:1
- OEM Part #: 43-45814A5
- Fitment: For drives with serial numbers up to 0K999999 (Gen II and below)
- Construction: Hardened, precision-ground marine-grade gears
- Condition: 100% brand-new SEI Marine replacement gear set
- Warranty: 3-Year Fault-Free Warranty provided by SEI Marine
Additional Information
Note: Fits Mercruiser 5.0L V8 sterndrives with I, R, MR, and Alpha I drives (1973–1990).
Not compatible with Alpha Gen II drives above serial number 0K999999.
All components required for a complete upper unit rebuild are available upon request, even if not listed online.
Shipping Information
SHIPPING: Additional shipping fees to Alaska, Hawaii, U.S. Territories, or international destinations will be calculated after checkout.
You will receive an email and a PayPal money request for the additional shipping charges at the email address provided.
(Some items are excluded from international shipping.)
Customer Support
For questions or to confirm compatibility, please email customerservice@marinepartswarehouse.com .
Please include your engine model and serial number to verify the correct gear ratio before ordering.
