The Yukon 3.90 ring-and-pinion set for GM 8.5-inch Olds rear axles is a durable replacement intended to restore correct ratio and torque feel. Yukon applies careful tooth finishing and heat-treat processes to reduce friction and heat while meeting OEM-spec fitment. The set carries Yukon’s standard coverage and is built to suit GM 8.5" rear cases where a 3.90 ratio is required for driveline tuning or restoration.
Yukon Gear High Performance Yukon Ring & Pinion Gear Set for GM 8.5in Olds Rear 3.90 Ratio