Back in 2006 you posted this info about the rear axle code (on the axle tube) for an 81 Chevy C10.
Hollander says RUB code is a:
41-15 (2.73) non-locking
10 bolt cover
8-1/2" ring gear
Chevrolet 10 pickup 78-80 conv. cab,
My 82 C10 has the GQ1 "standard axle" code and 4.1 six cylinder engine. Axle tube is stamped poorly, but looks like IUM. However, since the top third of the letters didn't get stamped, I guess it could be TUM or even TOM. Any idea what that tells me? I'm exhausted from searching!