Ready to do a Detroit Truetrac in my 8.6 10bolt NNBS. What all parts will I be needing? I will be keeping the stock 3.42's. So far I got:
1. Truetrac (go figure)
2. Bearing LM603049 X2
3. Race LM603012 X2
4. Diff cover gasket
5. Differential fluid.

I know I will need to verify backspacing, will I need to buy shims?
What about new bolts for the ring gear?

 

I always paint some gear marking compound on before I pull the stock diff out, check the pattern and backlash, and then repeat when I get the new differential in. As long as the pattern matches you're good. Every true trac I've done has had an identical pattern and backlash with the stock shims, so its basically just as simple as swapping the diffs out.