Very true. My old 70 sixpack RR, with a Dana 3.54, went something on the order of 80K, I don't remember, before the rear axle was ever touched. One bearing got a little rough, and finally started to make noise, so I replaced both bearings and seals.
The car had over 140K on the chassis when I sold it (stupid) and those same 2nd bearings were in it then
So in 140K, they were basically repacked ONCE.
I drove the sh** out of that car, and also did some trailer towing with it. Towed a 70 Cuda with all my extra junk loaded down from San Diego to N Idaho (North Idaho--it's a state of the mind)
