I think you mean the steering column. my truck (in my avatar pic) sits around 2 and half inches off the floor. its a rebody and it's not channelled. There is quite a lot of natural body drop on old truck cabs.
Yeh I meant column. I've been looking at a lot of pics and it seems like theres probably about 8" of 'door overhang' that would cover the chassis. I suppose there is a limit though, needing to keep the cab high enough to cover the engine. The other concern I think is getting the window/dash height correct, unless I want to be adjusting the height of the footwell, but I don't particularly want to.