Floorpans - Best Replacement Option?

[volaredon]

On my 78 d300 dually I used to have, I cut 6 pieces of sheet metal and welded those in to make a floor pan.
back then I had to bend the seat riser separate from the rest rather than hand forming it out of 1 pc like I've since learned to do.
anyway, on that 78 after welding in the home made pan I then hand laid fiberglass over the top of my replacement sheet metal. Not doing that part here.

 

[volaredon]

Had an 86 Ford 5 ton Louisville series truck that I had to make a pan for, I used a retired "road construction ahead" sign, a solid 48"x48" solid sheet of aluminum. I drilled and pop riveted that in a few years ago (I still don't know anyone who can weld steel to aluminum) I then used a couple of caulk gun tubes of silicone to serve as seam sealer. This was 2+ years ago and still solid...