A GM Dana 60 front axle uses 11/2-inch 35-spline inner shafts (left), and 1.31-inch 30-spline outer shafts with 1480-sized steering U-joints. Strong stuff to be sure, but on a truck that's going to weigh close to 6,000 pounds when it hits the trail, we needed to upgrade. Since we were going to require custom axleshafts anyway (for our 5-inch-wider axle), we stepped up to Dynatrac's competition series 35-spline inner and outer shafts. These chromoly gems are built by Superior Axle to Dynatrac's exacting standards for spline pitch, length, and seal surface finish. Extra material is added to the yokes to support CTM 300M U-joints, and the entire shaft (including the yoke) is heat-treated.