I replaced pinion bearings & carrier bearings at 172k, skipped axle bearings, got to do those at 200k. So, just do them now. If you use the same thickness shims (hell I just resued the same shims) and replace the bearings only, you should have no issues with pinion depth or backlash. My 8.8" went from screaming to silent when I reused the factory shims with new bearings, saved me from doing any "real" gear setup work. So long as its the same gearset in the same housing, that should work (bearings are pretty tight tolerance peices).

Do you mean you were hoping to get by replacing the four (not three) bearings & races? Two pinion bearings w/ two races in the housing, and two carrier bearings. Use a big brass punch for driving races.