- Mercury MerCruiser Alpha One 6 Cylinder Upper Gear Kit
- For use with:
- 6 Cylinder Inline (1.65:1 Ratio)
- R/MR/ALPHA ONE STERNDRIVE) 1983-1991
- R/MR/ALPHA ONE TRANSOM ASSEMBLY) 1983-1991
- Manufacturer: Sierra
- Model Number: Upper Gear Kit
- Part Number: 18-2257
- Also Known As: Mercury MerCruiser 43-803112T1