Speedo Cable

There are numerous screw sizes


This is he one I used in my 67 Dart.

It is the same for barracuda in 67 (should fit 68 -69) for length and trans end.

I just measured the speedo and it comes out to 5/8 - 18


https://www.classicindustries.com/product/1967/dodge/dart/parts/2822713.html


I don't know what meter you have . This is the first one I pulled up


5/8 - 18 thread