I'm talking about the one that threads onto the instrument itself. Right now I'm working up a set of 3.5 gallon fatbobs to use on my '74 ironhead for summer road trips to get better mileage & they came with the FXS/Sturgis tach & speedo dash. Both instruments are cable-driven. I'd like to convert my existing 12mm mini-gauge cables to work with the dash's gauges --- cables ain't cheap & I'd rather use what I've already got. I'm pretty sure I can do it with the speedo cable, which would require a 5/8"-NPT replacement nut (if I'm not mistaken), but I'm unsure if the tach cable nut can be slipped off/removed & swapped out.
Any ideas or suggestions would be greatly appreciated.