Look for a rebuild that has a corvette servo and stronger components...might as well be an upgrade!
Not 3 weeks ago by tranny needed replacing...just 3 days before needing to tow a U-haul to CA.

It wouldn't shift into 3 or 4 and there was metal in the pan when dropped. I reputable tranny guy said replace it. I couldn't afford him, so I found a company that rebuilds (truly rebuilds, not just refurbishes) many trannies (Allstar Automotive in Denver). Never having done it before, I dove in using the Haynes manual [-o< which worked fine.....this is a HUGE project.
I did't take pictures because this happened 3 days before moving to CA from Denver and I was totally on a mission....as well as my girlfriend!

GM calls for 9 hours. It took me 16 with Katie under there for 12

....A REAL BONDING EXPERIENCE WITH MY ROCKSTAR CHICK!!!
You'll definitely want to rent (if you dont have) a tranny jack, and also have another floor jack to hold up the motor. Many bolts or nuts are 15mm, but you'll need a wide range from 8mm-19mm, I believe. A breaker bar, 2x ratchet extensions and socket elbow are handy too. I highly (highly) recommend having another person to help with the latter steps of removal and then reinstall of the tranny itself. Here's a little idea of what is involved...from memory, so may not be complete and the order is not quite Haynes but will be fine.
1. Block van and put in neutral. (this is important when it comes to the park/neutral switch later)
2. Disconnect neg battery.
3. Jack up van and place on 4 jack stands. It needs to be high enough to roll the tranny out once its down on the jack. I think around 2ft or so, but dont quite remember. We had to "endo" the stand to get the bell housing clear.
4 Drain Tranny. Remove little heat shield passenger side.
4.5. Drain T-case.
5. Remove torsion bars.
6. Remove Front and rear drive shafts.
7. Disconnect 3x O2 sensors at connector side since exhaust will have to be dropped.
8. Disconnect starter (don't have to do the wires) and wire it to the body. Now you can get to the torque converter bolts.
9. Disconnect TC (3 bolts I think) You have to rotate fly wheel, I used a large screw driver in the little window that has the removable tab...drivers side bottom bell housing.
10. Disconnect speed sensor from T-case
11. Disconnect shifter cable from park/neutral switch.
11.5. Disconnect plugs from park neutral switch (these are very hard to remove for some reason. I was able to wiggle wiggle wiggle them loose but be careful not to pull out wires, I guess this happens a lot. Someone recommended a heat gun to loosen up the internal electric grease, but I didnt have one). **Also, not the little hash mark that indicates neutral because you WILL HAVE TO re-align this when putting the switch back on.
12. Disconnect exhaust at manifolds.
13. Place jack under T-case and remove mounting nuts from crossmember.
14. Remove cross member.
15. Slide exhaust off rubber mounts and lower (I had to lower my entire exhaust because it is one unit).I guess yo could also cut the exhaust with a pipe cutter and refit it with sleeves during the re-install.
16. Slide tranny jack into place and support tranny. Can now take other jack around to under motor. I placed wood in between the oil pan and used that to support motor.
17. Unbolt tranny (I think 6 bolts, 2 are on top and hard to see. Need extensions for ratchet)
18. Pull er' back, lower and pull out.
19. Disconnect t-case adapter from tranny (t-case is still connected, no need to disconnect that from adapter)
20. Clean surfaces then connect t-case/adapter to new tranny using new gasket.
21. ******Reinstall tranny making sure torque converter is properly placed as far back into bell housing as possible. If not, you will have a mis-stab and will fry your oil pump gear-thing. To do this push the TC all the way back into the housing so that when you reach fingers around perimeter, there is no gap. You will also do this just before actually moving close to bolt up, just in case it shifted during your many attempts to align the damn thing with the 2 tiny alignments posts on the motor.
22. Pretty much everything in reverse but take care on these 2 steps..
1. When threading the torque converter bolts, you should barely be able to. This means the TC is back far enough into the bell housing. The bolts will pull it forward just enough.
2. When installing the park/neutral switch, make sure the hash mark is aligned at neutral. If not, I think its click it all the way back, then 2 forward. You can use a wrench (12mm?) to do this. Remember PRND21. You'll know which is reverse out of park since its more of a click than the others.
**Be prepared to spend more time than you think realigning things like the tranny and exhaust.
So get this...I had it all back together, filled it and started it and cycled it through gears as directed..and it didn't work!! Wouldn't shift into gear!! I knew I took extra special care during the 2 technical cruxes so I was at a loss. #-o Had it towed to the rebuild shop and they first assumed I mis-stabbed the TC, which I was sure I did not. [-X I actually got a little pissed at them. When they dropped the pan, the fluid filter was cracked, so fluid wasn't flowing. I was so happy it was their faulty part

and not my amateur mistake!! =D> =D> =D> =D> =D> =D>
There you go! From memory...my brain hurts!!
hope this gives you an idea of the scope of this project...it was a major accomplishment for me....and my girl who had never even changed oil before.