U joint?

For the $15 is it worth all of that fussing around. The real test of joint failing is looking for marks on the bearing surfaces on the "X" . If these marks are something that can be felt with the touch of a finger, replace the joint.

Well it's a bit more than $15 but that doesn't bother me. My wife suggested getting the new ones and cleaning the old ones later. Keep them as spares or for originality. Probably go that route.

Well, If the measurements match a 4C then it's the 540. You must have a 4spd.?
At any rate if that turns out not to be right I now have pn's for 2C to 5C with maybe one exception (so far).
I went into the MT-52D and got busy. That PN you posted and I crossed to 540 isn't in there though but there are some that are real close sequentially. No idea why that is or how/where Southland got it.
The only one I haven't been able to cross from the K book is for early K1/2's with 3spd trans. it just seems to go POOF! It's not in any XR book,doesn't even open a web search. All I know is,it's a 2C,not a real problem since I did find pn's for 2C joints with threaded,drilled and 2 of each wings plus ones with wings and round bearings.

As for rehabing the old joint,not worth it IMO. When a winged type U-J fails the damage can be extensive,it's not uncommon for a wing to break which will usually cause the other to break,then the shaft to flail around and that can damage the weld yoke. To repair damage like that would probably cost 3 (or more) times the price of a new U-J.
So, is keeping them for "originality" even worth it? Not in my book.

I do have a 4spd. As for the south land one , I was only looking there in the hope that the k model used the same u-j as the d model. I'll try the 540 and see how it fits. The possible damage you mentioned is a concern I had, that's why I asked. Thanks again for the info.