84-87 GM Corporate 8.5" 10-bolt Posi side gears?

[84hurstolds]

I've managed to scrounge up most of the differential parts for my 28 spline 1985 442 3.73 10 bolt 8.5" with G80. Most all new GM parts except for the case and clutch pack, that's a repro from Bruce Ponti, and seemingly the hardest parts to find-- the side gears for the internal pinions. I don't guess I absolutely have to have them, but everything else is new, so I figured if I could find them, great. I suppose nobody makes them aftermarket new? (only GM number I could find for them is 407585, 231075 or 12471195). Anyone know where to find any?

Am I going to be stuck with the side gears I have? I would imagine I could swap them side to side if necessary, to put the main load on the other side of the teeth. Assuming they're in good shape. No reason to believe otherwise, they only have 60K miles on them. I mean, if they're in good shape and shim until I'm in the .001-.006 backlash, it should be fine, right?

I hate GM's parts catalog system. Everything listed it seems is for non-G80 unless it's a 7.5. The information for the 8.5" 10 bolt posi is limited, and in some cases, flat out wrong.