I just had a similar question about my 41 1.5 ton. It seems the cables are pretty hard to find for trucks this size, and most cables for cars aren't strong enough to move the shoes on suck a large truck. The best I found was a place suggested to me here in the forum try this place the don't stock cable for your year but they make cable for not much more than stock prices.
http://www.inlinetube.com/
Good luck, Rob

http://s1112.photobucket.com/albums/k483/Hotrod_A/
1941 1.5 ton