Mercruiser New Alpha One Upper

New Aftermarket MerCruiser Alpha One Upper Gearcase – Fits Alpha One I/O, R/MR (1972–1990)

This Mercruiser Gen II upper unit is a high-quality aftermarket replacement designed for Alpha One I/O and R/MR outdrives, specifically fitting models from 1972 to 1990. Built to deliver reliable performance across a range of gear ratios, it’s the perfect solution for restoring your upper unit without compromising on quality or durability.

The unit supports the following gear ratios:

1.47, 1.62, 1.62 Short Yoke, 1.81, 1.81 Short Yoke, 1.94, 1.94 Short Yoke, Made with non-OEM components, this upper gear housing offers a cost-effective alternative to expensive original parts. Whether you’re working on a 5.0 Alpha One MerCruiser, exploring compatibility across Gen 1 and Gen 2 differences, or simply looking to replace worn MerCruiser upper unit gears or gear housing bearings, this is the unit for you.

Pricing

• For pricing and core deposit details, please call 913-342-0011
• Core rebate amounts depend on the condition of your existing unit.

Product Finish:

• Premium-grade aftermarket housing
• Precision-machined gear compatibility
• Designed for Alpha One Gen 1 upper unit configurations

Core Rebate Information

• Return your old core, get up to $200 back
• Rebate amount will vary based on the condition of your core
• ♻️ Recycle your core- keep boat parts out of the landfill

Useful Resources

• 🔍 How to find your Boat Engine serial number? 
• Still deciding? Watch our YouTube video How to avoid common lower unit replacement mistakes
• To help extend the life of your gearcase, check out our Boat Maintenance Checklist