RP GM 8.2in 3.73 64-72 M GP

The RP GM 8.2in 3.73 64-72 M GP by MOTIVE GEAR is a ring and pinion gear set engineered for classic Chevrolet and GMC trucks built between 1964 and 1972. This complete differential ratio upgrade replaces worn factory gearing and enables enthusiasts to optimize engine torque delivery, improving both acceleration and fuel efficiency across the RPM band. Whether you're restoring a vintage pickup or modernizing a classic drivetrain, this 3.73 ratio delivers the performance gains and reliability that serious mechanics demand.

Manufactured by MOTIVE GEAR, a trusted supplier of OEM-quality and performance differentials, this 8.2-inch ring and pinion set is precision-cut and heat-treated to withstand the demands of both stock and lightly modified engines. The 3.73 gear ratio provides a balance between low-end torque multiplication and highway cruising efficiency—taller than aggressive 4.10 gearing but more responsive than stock 3.55 configurations. The assembly features durable cast iron and hardened steel construction, ensuring extended service life when properly installed and maintained with quality differential fluid.

This ring and pinion kit is ideal for owners of 1964–1972 Chevrolet C10, K5 Blazer, and GMC pickups seeking improved acceleration without excessive fuel consumption or driveline stress. Installation requires basic differential service knowledge or professional shop support; verify your existing carrier type and ring gear diameter before purchase to ensure compatibility with your specific rear axle housing. The compact 11.2 x 5.2 x 15.3-inch package ships ready for installation and pairs seamlessly with stock or mild performance upgrades.