The new 2nd generation alloy steel U-bolt kit is a result of information gained on our drive shaft Torsion testing machine. We found that the standard 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 rock out of the differential companion flange. By surrounding the joint cups a full 360 degrees with support up to 500 additional foot pounds of torque was possible. These 2nd generation U-bolt 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. Sold as sets with accompanying 12 point reduced double hex nuts. Fits all current Mark Williams forged billet rear pinion yokes.