C6 Output Shaft Options

[colnago]

I'm rebuilding a C6 from a '71 that I'm planning to swap into my '67. It already has a C6 in it, so I figured it would be a fairly simple swap. However, the '71 has a short output shaft, and mine has a long output shaft. I figured all I had to do was get a long output shaft and housing for my rebuild, which I did. But the output end is different. It doesn't have the threaded end for the U-joint (does that mean it's from a car, and not a truck?). So now I have the following options:

1. Rebuild with the long shaft that I have, and find the appropriate U-joint collar at the junk yard.
2. Use the short output shaft, and find a longer driveshaft at the junk yard.
3. Wait until I pull the C6 in the truck, and use its output shaft and driveshaft.
4. Forget the C6 from the '71, and just rebuild the C6 that I have in the truck.

I don't have any reason to think either tranny needs a rebuild. I just figured that since I'm already rebuilding the engine, that I'd rebuild the tranny, too, and get it all done. I have found some wear in the thrust washers in the '71 C6. Wouldn't you know, there are no thrust washers in my rebuild kit!

So, any opinions?

Joseph

[colnago]

Well, I think I've resolved my issue. The longer output shaft (31 groove) uses a slip yoke. If I complete the rebuild with the long shaft I have, it will be a complete replacement of the current tranny. The slip yoke will pull off of the existing tranny, and slip onto the new. So, now I just need to decide if I want to stick with the long tail, or find a new driveshaft, and (re)convert to the short.

Joseph