I orginally started this thread in the brakes and suspenstion, but it should really belong here. Let me do a quick rundown.
I have bought a 12 bolt rear that I believe is out of a 70 chevelle. It had on open rear that I am putting a lockright locker into. The lockright locker says to reuse the thrust washers (I think that is the right term).
Just to make certain everyone knows what I am talking about this is the washer that sits between the back of the drive gear in the open diff and the carrier case (the axle runs through it).
Long story short is that I can not find a new set of these. GM claims they do not carry them. I got a p/n of 393578 from another forum but I can't match that up with a part yet (I just called GM and that p/n isn't in their system anymore either).
PS~Can someone tell me when you refer to a "spider" gear is it only the small two gears? I had been under the assumption they were all four spider gears, but I believe the two larger ones are "drive" gears? This has caused me some confustion when explaining what I have been looking for.

I got some thrust washers a few years ago from Reider Racing. They specialize in differential parts.

The drive gears are the ones that are splined and your axles actually engage. The other two are spiders.

Been a while since I've been in one to know which were big and little, but you are using the correct terminology.

Why dont you just use the existing thrust washers out of the open carrier?

Its good to know I'm finally getting the terms right. I would love to reuse the old ones, but something really bad happened to one of them. It looks like the surface of the moon. It has some bad pits and weird galled marks. I'm not sure what happened. The case looked fine as far as I could tell.

The guy from "US Gear/Strange" has already mailed me the parts. I haven't even paid for them let! Very professional. I am impressed! I just hope they are the right part.