Not sure about the threads, but looks similar: Speedometer Gear, Ratio Adapter, Speedometer Cable, Speedometer Gears
Part way down the page under GM /Dodge/Ford Ratio adapter
As I recall the adapter threads didn't fit the cable exactly and Olthoff said to use antiseize and carefully force thread mating at that connection.
I had figured that so many people switching to electronic setup that there would be some floating around, but I will look into that site you sent, thanks
