I'm also interested in upgrading to power steering.
1962 c60, 18ft flatbed, L6-235, 4spd w 2spd rear axle.
This is the best I've found so far:

http://67-72chevytrucks.com/vboard/showthread.php?t=578151

I'm getting the feeling without pulling PS off an identical (nearly) truck, will take some fabrication. Lots of kits for c10,20,30 not sure one of those would work, but have to be improvement over no PS at all....?