Hy lunchbox, you will gain some clearance when the mast jacket is removed, but I don't know if you can move the steering box outboard enough to get the clearance you will need. There are kits available to mount later GM power steering boxes to the front of the left frame rail, but these are car or pickup boxes at best and I would be concerned that they were strong enough if you ever taxed the truck to its design limit. If you tried searching for "power steering conversion" you might find some tips, I think Grigg suggested a Toyota steering box, and quite a while ago an Isuzu NPR was mentioned, hope that helps.
