The SR-4 was made from 1980 to 1981 to be used with a D-300 transfer case. This transmission is a fully synchronized 4 speed, completely rebuilt with upgrades to help with longevity and strength such as torque lock sliders. The transmission has a 10 spline 1 1/8″ diameter input. This does not include a shift tower. There is a $200 core charge.
| 1st Gear | 4.07 to 1 |
| 2nd Gear | 2.39 to 1 |
| 3rd Gear | 1.49 to 1 |
| 4th Gear | 1.00 to 1 |
| Reverse | 3.95 to 1 |