Originally Posted by Bavo76
you will need a mig welder and its going to be hard going welding while on your back under your bus and getting the panels to meet over a cross member or you are going to have to put more bracing in
No laying on your back is needed. Drill half inch holes through the new metal floor sheeting over the cross members, and simply plug weld.
Mig welder or Tig would be the way to go.
Wood floor is fine as long as the part where you sit while driving is steel. More times than I can count I have had things hit the floorboard under my feet hard enough to punch through a wood floor, but only dent a steel one. One time on my Bronco 2, the drive shaft broke just behind the transmission. Still attached to the rear end, it dug into the road, and blew through the floor board right behind me. Good thing my kids weren't in the back seat.