Eaton Posi Performance Differential GM 87+.

Chevrolet: 7 5/8 in. (7.625) 10-bolt axle, 3.23 and numerical higher gears, 28-spline axles, differential. Big tourque doesn't have to mean big traction problems. Eaton Posi Performance differentials combine carbon friction discs and precision forged gears to give you great traction, even under higher torque loads. Plus, the carbon friction discs produce smooth, quiet performace for the life of your vehicle.