Rebuilt 8.75 Sure-Grip - resistance and clunk
So, both the shop and some testing on my old rear end would indicate that the rotational play is normal. That said, I took it on a longer (as in around the block outside my driveway) drive and something has got to be wrong.
I found a big parking lot and did a dozen low-speed figure-8s. Each time the inside wheel chirps, hops, and bangs 3-4 times. It didn't get any better with more figure-8s, if anything it got slightly worse. The car puts up quite a fight when making a tight turn, especially on the inside wheel. Going straight feels bit better, but there's a whine on coasting that sounds exactly like a police siren.