MerCruiser Alpha Gear Tooth Ratio Chart Made Easy – Full Chart Inside
If you’re trying to identify the correct gear ratio for your MerCruiser Alpha One, Alpha One Gen 2, or even earlier R-style sterndrives, this gear ratio chart will help you quickly match engine specs to gear ratios and tooth counts. Whether you're searching for the MerCruiser Alpha One Gen 2 gear ratio chart, the Alpha One gear ratio, or how to find gear ratio on a MerCruiser outdrive, this guide provides a complete breakdown of gear ratios by engine type, horsepower, cylinder count, and model year.
Use this chart to compare Alpha 1 Gen 1 gear ratios and Alpha 1 Gen 2 gear ratios, or reference specific configurations like the MerCruiser gear ratio by serial number.
From 3.0L to 5.7L models, and everything in between, this is your go-to MerCruiser gear ratio chart for fast and accurate identification.
Mercruiser R-Style Sterndrives (1969 – 1983)
| Engine | HP | Liters/CID | Cylinders | Gear Ratio | Tooth Count | Year |
|---|---|---|---|---|---|---|
| 2.5 Liter | 120 | 2.5/153 | 4 | 1.98 | 20-24 | 1969-1983 |
| 2.5 Liter | 130 | 2.5/153 | 4 | 1.98 | 20-24 | 1969-1983 |
| 165 | 165 | 3.7/224 | 6 | 1.65 | 24-24 | 1969-1983 |
| 470 | 170 – 190 | 4.3/262 | 4 | 1.84 | 17-19 | 1969-1983 |
| 215 – 233 | 205 – 230 | 351 | 8 | 1.5 | 20-22 | 1969-1983 |
| 260 | 260 | 5.7/350 | 8 | 1.5 | 20-22 | 1969-1983 |
Mercruiser Alpha 1 (1984 – 1990 Models)
| Engine | HP | Liters/CID | Cylinders | Gear Ratio | Tooth Count | Year |
|---|---|---|---|---|---|---|
| 2.5 Liter | 120 | 2.5/153 | 4 | 1.98 | 20-24 | 1984-1990 |
| 3 Liter | 130 | 3.0/181 | 4 | 1.98 | 20-24 | 1984-1990 |
| 165 | 165 | 3.7/224 | 4 | 1.84 | 17-19 | 1984-1990 |
| 175 | 175 | 4.3/262 | 6 | 1.84 | 17-19 | 1984-1990 |
| 180, 190, 470 | 180 | 3.7/224 | 4 | 1.84 | 17-19 | 1984-1990 |
| 200 | 200 | 5.0/305 | 8 | 1.65 | 24-24 | 1984-1990 |
| 205 | 205 | 4.3/262 | 6 | 1.84 | 17-19 | 1984-1990 |
| 230 | 230 | 5.0/305 | 8 | 1.5 | 20-22 | 1984-1990 |
| 260 | 260 | 5.7/350 | 8 | 1.5 | 20-22 | 1984-1990 |
| 350 Magnum | 270 | 5.7/350 | 8 | 1.5 | 20-22 | 1984-1990 |
Mercruiser Alpha 1 Gen 2 (1991 & Newer)
| Engine | HP | Liters/CID | Cylinders | Gear Ratio | Tooth Count | Year |
|---|---|---|---|---|---|---|
| 3 Liter | 130 | 3.0/181 | 4 | 2.0 | 24-24 | 1998-2005 |
| 3 Liter | 130 | 3.0/181 | 4 | 1.94 | 20-24 | 1991-2005 |
| 4.3 Liter | 175 | 4.3/262 | 6 | 1.81 | 17-19 | 1991-2005 |
| 5.0 Liter | 230 | 5.0/305 | 8 | 1.61 | 24-24 | 1991-2005 |
| 5.7 Liter | 260 | 5.7/350 | 8 | 1.47 | 20-22 | 1991-2005 |
Final Tips on Finding the Right MerCruiser Gear Ratio
Still unsure or want to double-check your setup? You can also reference your MerCruiser serial number or consult your engine’s service manual for confirmation.
And if you need help, give us a call at 1-856-232-6969 — we're happy to assist.
Bookmark this page or share it with fellow boaters — having the right MerCruiser gear ratio chart on hand saves time and avoids costly mistakes.
Recent Posts
-
Eco-Friendly Boat Shrink Wrap for Winterizing
Winter's chill is on its way, and boat owners know it's time to shield their vessels from the cold. …September 15, 2025 -
MerCruiser Alpha Gear Tooth Ratio Chart Made Easy – Full Chart Inside
If you’re trying to identify the correct gear ratio for your MerCruiser Alpha One, Alpha One Gen 2, …August 23, 2024 -
MerCruiser Exhaust Buyers Guide
May 13, 2024