The 2nd generation alloy steel U-bolt kit is a result of information gained on our driveshaft torsion testing machine. We found that our older version, 3/8" 1350 u-bolt was prone to cycle failure when cycle testing at high torque levels. The one-piece U-bolt was allowing the joint to rock out of the differential companion flange. By surrounding 360 degrees of the joint cups with support, up to 500 additional foot pounds of torque was possible. These 2nd generation U-bolt (cap) kits feature a bubble stud that locates on the rear flange bolt hole indexing the location. The straps are produced from a pre-heat treated chromium-molybdenum steel. The studs are 150K material with rolled threads. Includes  two caps, four bolts, and four 12 point reduced double hex nuts. Fits all current Mark Williams forged billet rear pinion yokes and rapid release transmission yokes.