Hy lunchbox, the steering column is not removeable other than by cutting/pulling the mast jacket off and modifying the shaft by cutting and adapting a "U" joint. You will have to move the box outboard quite a bit to clear a big block (if there is enough room to do that). There are other boxes that you could install in place of the original steering box, a lot depends on how hard you're going to work your larger truck, hope that helps.
