I had the gears in the rear axle on my 2WD truck swapped at Randy's Ring and Pinion up in Everett a couple of years ago. The service and work performed was excellent in every way.
Once they had the original gears out, they took me out to the shop and showed me the clutch-packs of the limited-slip carrier was well worn. Also the pinion bearings and carrier bearings showed signed of moderate wear. It was my decision if I wanted to replace any or all. I decided not to cut corners and had them replace everything. I paid a little extra and had them use new Dana gears too... not that there's anything wrong with other brands mind you. I just wanted to go with a brand I could trust.
When they were finished with the work the truck was clean and the differential had a freshly painted cover. At my request, they gave me back the original gears nicely cleaned and stored in a box just in case I ever wanted to change the axle ratio back.
I would definitely use them again.
Best regards,
John L.