Well, I bought the Crown kit from Summit Racing that AMC of Houston mentioned and compared it to the one from RockAuto and they seem identical. I then took them both to a different transmission shop and asked them to rebuild my clutch cylinder.
I got a call the next day; it turns out that neither of the kits will fit my master cylinder. He had my cylinder taken apart on the bench and showed me the original seals vs. the ones in the kits, and both of the kits were visibly smaller in diameter. I don't understand what's going on, unless some previous owner replaced my cylinder with a non-standard one. He is now trying to look at other random rebuild kits to see if he can find one that will fit. The whole situation is pretty discouraging. This may be the issue that makes me just walk away from my Eagle.
If anyone is looking at this thread because they are trying to rebuild their clutch master cylinders, all I can tell you is that neither the RockAuto or Crown kit will fit my 1984 5-speed Eagle.
JB