Well damn! You sure all the spider gears are intact and all ? They look fine through the holes, it spins smoothly, ?
Have you opened it up to check the upper and lower gear?

What about your transfer case, have you pulled it off and check to see if it spins freely ?

What about each drive axle, any up/down play in any cv ?

Do you still have the stock line with check valve in it running to the brake booster ?