OK, I just got a used set of GM 4.11's. They came with the pinion bearings. I don't know how many miles on them, so I was going to reuse my stock bearings. Also I was going to try my stock shims first. How do I remove the large main bearings near the gear? Should I soak them in gear oil and py them off? Any suggestions would be great on this. thanks.

 

You're probably going to need a bearing puller to get that off. You should be able to get one at any place that sells automotive/industrial tools. As a rule, the pinion bearing is pressed on there pretty tight.