Speedometer Cable?

[cptstickfigure]

Anybody who's done a T5 swap, what are you using for a speedometer cable? Is there an off the shelf solution?

I've got an '83 S10 T5 and a stock '64 C10 speedometer. The old cable is too short, obviously, so I tried replacing it with an '83 S10 and '79 C10 cable. Both of them were long enough and fit the transmission, but they didn't have a collar for the speedometer end. It was like they were just supposed to push in and stay put, but they fit like there was supposed to be a collar (make sense?). Am I missing something? Did I get incomplete cables? Is that how they're supposed to work?

I saw something on this board about using a same year 4x4 or big truck cable, but I seem to recall the transmission end of the older cable being a different size than the T5's.