73 Duster Speedo cable - tranny side

So I have a /6 base duster auto. I got a new speedo cable and the gauge end is correct (plastic snap on) the tranny side is totally different. It has a 7/8" threaded cap that holds the end on while the cable has a smaller 5/8" hand thread nut. I searched parts lists and it keeps showing me the new one I have.

How do I find the right one? Maybe another year/model?

Thanks,
RGAZ