That's what I'm saying if the ball does not fit through the hole on the bottom of the sift arm that's good...
Put a slit in it somewhere so just the cable will fit (kind off like how the other side mounts to the gearbox). That should hold it in place, and if you have a welder you can tack the slit closed if your afraid it will slip back out.
Or if the hole is too big and the ball will just slip right through it, find a washer, or something like it, that the ball will not squeeze through, put a slit in it...
once you feed the ball through the hole on the shifter, slide the washer (that is slit) through the cable. Now the ball will not pass back through the shifter, you can tack weld, tape, or jb weld the washer in place so that it doesn't move.
I have a dremel with a cut-off disk, and that Is what I use to make small slits like what I'm talking about.
here are a couple pics of my setup. The shifter that I use is old, you push forward instead of pulling back to go into reverse. I don't like it too much but it works for now, I plan on getting one of the ones from the kit pretty soon. If you look at the first pic you can see the tab I welded on to hold the cable adjuster part in place, I just drilled a hole big enough for it to fit through and slit it with the dremel. The cable is held on to the shifter by a wheel collar like this...
http://www.ebay.com/itm/RC-Airplane-...#ht_738wt_1396
T.J.