If we're talking about a 10-bolt 8,5 rear axle, the thing is totaled when the gear lube gets old.
There is NO WAY I'd blow money on a replacement axle shaft or two, when for a little more, you could replace the weak and fragile 8.5" axle with a 9.5" axle assembly.
ANY aftermarket axle shaft from a reputable manufacturer is likely to be
at least as good--and probably better--than the OEM axle shafts. No promises on cheap-junk Chinese axle shafts.
Moser, Currie, Strange, and probably 5 others I've forgotten. I'm not sure how you can't find them.
In no particular order:
1. Yukon
2. Motive Gear
3. Richmond
4. Summit Racing (house brand)
5. Mark Williams Enterprises
6. Alloy USA
I've got a pair of Alloy USA axle shafts in the barn, too lazy to cram them under the 'Camino.