Speedometer Cable Nut

I'm pretty sure the trans is from the early 70's, I don't recall this being an issue when I bought the speedo cable, the only issue I remember was there were two different lengths to choose from.

Just spent 20 mins going thru old parts receipts and found the speedo cable and the nut size is 13/16".
And all that info will help other members know if they have the correct nut you asked for. Good luck.