I found a place that sells stud girdles (covers) for the 9 bolt rear. It is $159. Are they worth it? Do they really strengthen the rear end? I dont want to waste $159 but if it does strengthen the rear I will buy it. Who runs one and what is your opinion?

 

alot will depend on how you define worth it, but yes they strengthen the rear, aong with welding the tubes to the center section.

 

When you accellerate hard, the pinion is trying to force it's way out the front of the diff. That's why a solid pinion spacer is prefered. It can't be compressed.

At the same time, the ring gear is trying to go out the back of the diff. Although the bearing caps do a good job of keeping it in place, the case still flexes from all these forces. The solid rear cover with bearing cap supports helps to keep the caps from flexing. The bolts that push against the bearing caps are only torqued to 5 pounds so it doesn't take a lot to keep them in place.