Its a common issue to crack the Hummer H1 Frame by the steering box. This kit reinforces the frame and fits tighter to the frame than any other kit. It also does not go under the bolts that hold the steering box, this is key. Kits that go under the bolt heads put the bolt heads at an angle and increase the load on the bolts. This makes the bolts weaker. This kit welds to the frame and to the bosses to make it a much stronger design. Also note the welding slot that makes it easier to install on the truck, and does not require the upper control arm to be removed for welding.