Oh, and for what it's worth, I got a fairly good look at the floorpan while swapping out the seats. It's in excellent shape. Very solid all the way under the sill plate. Sure, my outer (and probably inner) rockers are shot, the bottom of my doors are gone, the cab corners are, well... not there, and my cab struts are swiss cheese, but at least I've got
some good metal in there!