Sorry…I was sidetracked from the 425 when my TrailWagon broke a shift cable. I was trying my hand at soldering a barrel end on. (So far nothing but failures—I have two ordered, but…I still have to try LOL)I don't really understand what you’re trying to do here, a pic might help. Did you ever try the cable clamps? Like a miniature heavy duty muffler clamp. You could either collapse the eyelet onto the cable, or clamp it along side. Just a thought.
I had to cut off existing barrel end of a new cable and run it into the stock outer cable housing—it has the curved metal threaded end with two adjusting nuts. The cable goes into the side of the barrel. The barrel fits into a half round “rotor” on side of transmission for one direction. Another cable fits into the rotor as well for the opposite direction. The rotor rotates, pulled or pushed by the cable/shifter.