Mine was like that too. The adjusting screw is on the back side of the box next to the frame. It did no good.
I took it to a steering rebuilder nearby and they went throught it for only a hundred bucks or so. Money well spent!
I'll suggest a couple flex bars and six point sockets if you remove the box.
I don't think power steering was an option on the '60-'66 4x4's
