1971-91 GM Dana 60 4340 Chromoly Discovery Series Front Kit, 35 Spline, HD U-Joints Revolution Gear and AxleRevolution Gear and Axle Discovery Series 4340 Chromoly Front Axle Kit, fits 1971 91 GM with Dana 60 and 35 Spline Axles. This kit replaces the Spicer 5 806X u joints with Revolution Gear and Axle HD Chromoly u joints. These u joints are a non needle bearing design and must be maintained, not recommended for daily driving. This Revolution Gear and Axle Front Axle Kits comes with Qty2 35 Spline 4340 Chromoly Inner Axles Qty2 35 Spline 4340 Chromoly