So I've been looking to rebuild the diff in my stealth as well as replace things like the idler shaft. I went into my LHS which had the parts but the guy couldn't find the diff rings and a couple of the smaller pieces.
I was able to get the 6581 3/32 carbide diff balls, 6570 idler shaft and the 6580 diff gear. The rest, came from the TC3 diff rebuild kit 3926 instead of getting 6573 differential thrust washer and 6575 thrust t nut and 6579 Differential drive rings.
Everything fit perfectly! I already had a B4 topshaft so only thing left if I want it brand new is new bearings.
Thought I'd pass this info along in case you wanted to do this too! I just took the car for a spin and it works great