Rather than hi-jack the other thread I'll answer your question here,
My cab is bolted through the floor solidly to the frame via the big sheet steel that serves as my inner box liner too. 5 bolts 6" apart. front to rear both sides
the "over the cab box" was welded solid to the roof steel, then the roof of the cab was cut out.
the two angle sheets on both sides are welded solid to the cab walls the front step sheet and the tubing for those walls placed at both the outer sections which are tied together across the top.
the structure of my basement storage box area is very rigid, not much flex in the frame anywhere, so all the work is done with the springs, like a well built race car.
I haven't noticed any thing negative yet, most motor-home campers are attached solid to the cab, go to a rv store and check it out. I hope not to ever have to off road it mush more than a campground spot, and then I will be very gentle and with my low ground clearance I'll try not to hang it up on a high spot or twist it to the point where I have to worry about things like the windshield cracking, which I think would be my weak spot.
