Thanks guys!

As it turns out, it is OK. I took my other wheels and tires up to the shop today and we swapped them out. It was probably the tires... because now it is fine - smooth as glass!

Although, Jim, you may be spot on... when he jacked the car up, he put the floor jack under the diff, which lifted the whole rear end off the ground, and the springs might have set once the load was off.

Either way, it's in good shape now. Next on the list is to get it 4-wheel aligned. The method they used to get the diff out allows for misalignment after reinstall.

I'm really hoping to get it done this week so I can hit the track on Friday or Saturday. I think this is the last weekend that the track will be open until spring.

Cross your fingers!