Does it have an I beam front axle or independent suspension? I used a steering box from a '74 C-60 on my '66 C-60,and it fit without mods. (never hooked up the hydraulics,it drove fine without it.)Only problem I saw was the drag link was a little different length than the original,so I had to re-center the steering wheel and it turned a little sharper one way than the other. That could've been easily cured by matching the length of the newer one to the original. The set up I used had a ram that had one end attached to the tie rod with clamps and the other end connected to the center of the axle,which would require making a bracket since there's no hole for it to bolt to,the hoses would've been the right length to use as is,the set up also came with a cooler.The donor truck had a V-8 so the pump brackets wouldn't fit my 292 six,but that's not hard to cure either.
Basically an easy swap,but requires some parts searching and a little fabrication.
Don't know how much of this will be of use to you,but hope it helps.
Speed