Has anyone rebuilt their auto box?

Well, trying that is one way to make sure the band goes. As long as the car's trying to move while you're doing that, your transmission's still working.

edit: Seriously though, autos should be left to the pros. You can find probably a half dozen stories just on this board of people who broke their cars trying to rebuild or even just service their own slushboxes and I can't actually recall a single success story. And these are not complex transmissions, this is a 1970s design. You're just going to drop a few hundred on a rebuild kit, fluid, and some tools and end up with a broken car.

The car's already broken. The reason I tested it is because the RPMs would race at a stop light for 1-2 seconds before the car would begin to move. The procedure was the stall test described in the FSM on AT-87. I'll pull it and take a look before I buy anything. I suspect all the bands and cluches need to be replaced along with a very thorough cleaning. The fluid is black with ~5000 miles on it.

Oh, well, proceed then

edit: you might try just cycling the fluid and filter again first and see if it helps, if your fluid is cooked your tranny's going to work like shit anyway. The lines to the rad are easily accessible so you could try the pump-through thing with the motor running to get it all. Cheaper and way less time than a rebuild kit for a tranny you're going to junk anyway…?