This would be a lot of work but you might try to find a power assist steering set up off a early sixties Chevy car. The assist works on the steering linkage rather than through the steering box. I had power steering on my 64 impala and loved it. Silk smooth. The hardest part would probably be getting the control unit attached to the pitman arm. And who knows, that control unit may bolt right on a big bolt pitman arm? I have a friend that did a lot of mods on his Scout, and he took two pitman arms and weled them together. I would be hesitant to try that method. If you weld breaks you have nearly four tons of out of control Chevy steel on your hands! It would take some work but if you got it to work you would be a big bolt hero!