Swapping from 3.42 to 3.73 was one of the best performance mods I did to mine.
I actually took the gov-bomb out. Had a 10 bolt Chevelle rear-end that had been hanging around for years. I knew it was a posi, but I had never opened it up. Almost sold it a week before the diff. in my truck imploded, for $200.00. Good thing I didn't sell it, 'cause when I opened it up, it had a almost new Auburn posi inside!
Gonna go through it before you install it? Lot easier to change the bearings & stuff on the bench than in the truck.