Ring & Pinion GM 8.5 4.10

The Ring & Pinion GM 8.5 4.10 from Allstar Performance is a precision differential gear set engineered for GM 10-bolt rear axles, delivering the gear ratio control essential for high-performance applications. This 4.10 ratio setup is purpose-built for users requiring enhanced acceleration and lower-gear pulling capability—critical for vehicles demanding aggressive torque delivery across competitive, off-road, or heavy-load scenarios. Whether optimizing a street performance build or maintaining factory-spec replacements, this ring and pinion combination addresses both OEM restoration and modified platform needs.

Engineered to OEM GM specifications, the Ring & Pinion GM 8.5 4.10 features a 30-spline pinion shaft designed for robust engagement and load distribution across the 8.5-inch differential housing. The 4.10 ratio produces tighter revolutions per mile relative to stock gearing, translating to reduced engine RPM at cruising speeds while maximizing torque multiplication during acceleration. Manufactured to exacting tolerances by Allstar Performance, a trusted supplier to racing and restoration shops nationwide, this kit ensures proper mesh geometry and backlash for extended service life and consistent performance under demanding conditions.

This ring and pinion set is ideal for GM 10-bolt differential platforms found across light-duty trucks and performance vehicles from the 1970s forward. Installation requires professional differential service and proper bearing preload setup; this is not a bolt-and-go component and demands experienced technician labor or advanced DIY capability. The 18.15 lb kit ships complete for full differential assembly, making it suitable for both restorations seeking original specifications and modified builds pursuing aggressive ratio tuning for improved acceleration response.