Revolution Gear and Axle Discovery Series D60, 4340 Chromoly Front Axle Kit for 71-91 GM. Kit comes with 2 35 spline inner axles, 2 35 spline outer stub axles, 2 Dana Spicer 5-806X U-joints. All Discovery Series Axles are backed by a 10 Year Warranty covering manufacturing defects and axle breakage, bent axles and twisted splines. This warranty is non-transferable. U-Joints are only covered under warranty for 1 Year (Other than Revolution Gear HD Chromoly U-Joints). Parts subject to normal wear are not covered under warranty; this includes bearings and seals.