3.73 Gear Ratio. 3.73 gears are a great combination of performance and fuel economy that's ideal for a daily-driven 'Stang that sees a lot of highway time. If you put a lot of miles on your Pony and don't want to increase your cost at the pump, a 3.73 ratio will still give you the added acceleration you want without compromising fuel economy dramatically.
Superior Construction. These Motive ring and pinon gears are CNC cut from high grade 8620 gear steel, and factory lapped for precision fit. Each set is hardness tested prior to leaving the factory to ensure the highest quality.
Recommended Upgrade. Changing the rear axle gear ratio will throw off the calibration of your Mustangs speedometer, but a new Speedometer Gear is an inexpensive way to fix this issue.
Application. This Motive Performance Plus Ring and Pinion Gear set will fit all 1979 to 1985 V8 Ford Mustangs equipped with a 7.5" rear end. A master bearing kit is recommended by most installers, especially on high mileage vehicles, see drop down option above.
| Approximate RPM for 1979-1985 GT Manual | |||||||||
| Gear | Speed | ||||||||
| 25 MPH | 35 MPH | 45 MPH | 55 MPH | 65 MPH | 75 MPH | ||||
| 1 | 3876 | 5427 | 6977 | ||||||
| 2 | 2289 | 3205 | 4120 | 5036 | 5951 | 6867 | |||
| 3 | 1530 | 2142 | 2754 | 3366 | 3978 | 4590 | |||
| 4 | 1150 | 1610 | 2070 | 2531 | 2991 | 3451 | |||
| 5 | 771 | 1079 | 1387 | 1695 | 2004 | 2312 | |||
| Approximate RPM for 1979-1985 GT Automatic | |||||||||
| Gear | Speed | ||||||||
| 25 MPH | 35 MPH | 45 MPH | 55 MPH | 65 MPH | 75 MPH | ||||
| 1 | 2761 | 3865 | 4969 | 6073 | |||||
| 2 | 1687 | 2362 | 3037 | 3712 | 4386 | 5061 | |||
| 3 | 1150 | 1610 | 2070 | 2531 | 2991 | 3451 | |||
| 4 | 767 | 1074 | 1380 | 1687 | 1994 | 2301 | |||
Technical Note. Installation costs will vary, but a good rule of thumb is between $250 and $300. Be sure to work with a reliable shop that you trust for installations.
Mustang Fitment: 1979, 1980, 1981, 1982, 1983, 1984, 1985 Details >>
