3.90 63-79 Corvette

The Richmond 3.90 ring and pinion gear set for 1963–1979 Corvettes is a direct-fit upgrade designed to enhance rear differential performance on classic Corvette platforms. This component is essential for any serious Corvette modification, providing precise gear ratios that optimize acceleration response while maintaining cruising efficiency. Whether restoring a stock C2 or C3, upgrading from worn original gearing, or building a restomod, the 3.90 ratio is an excellent choice.

Engineered to OEM-equivalent tolerances, Richmond ring and pinion sets feature precision-cut spiral bevel gears that minimize noise and wear compared to older spur designs. The 3.90 ratio enhances rotational velocity in lower gears, resulting in quicker acceleration while keeping engine RPM manageable at highway speeds, typically around 2,200–2,400 RPM at 60 mph, depending on tire diameter and transmission. These gears are also finished to resist corrosion, ensuring durability and longevity.

Classic Corvette owners, restoration specialists, and restomod builders will find the 3.90 ratio to be a valuable addition, as it allows for a direct, bolt-on performance upgrade without the need for fabrication or modification to the original differential housing. This makes it an ideal choice for mechanics looking to enhance the driveline character of their classic Corvettes while maintaining period-correct specifications.