Can see the seat mount right next to the raised section of the support giving it greater strength. I left as much as I could of the original reinforcement it was welded too, so it now has three layers of steel above it. The pocket you see at the end of the sill support is the bottom of the B pillar and what I made into the rear body mount. This new support should help with that as well.
So this I think should be adequate for supporting the longer and wider floor. At the top left of the photo, where the rear support is in the middle of the transmission tunnel, you can see what was the outer mount for the fuel tank. That is now mounted off a chassis cross member and I will use this mount now as an additional body mount in the middle of the rear part of the cab. On the right photo, just thought I would show this simple mod that worked so well. Rather than fill the void above support flange where the rib in the floor is with sealant, thought I would try bend the flange instead. Started with a rounded end on a cold chisel. Lined it up directly in the middle of the gap with the chisel on the edge of the flange and angled back.
One hit with a mallet and done! Time to move onto the front cab mounts. I had a good pair of original Willys front cab mounts that were rust free after cleaning them up in the citric acid bath. Was hoping to use them on the donor firewall.
But the fold on the donor firewall sits a lot lower than it was on the Willys. That rear brace support is supposed to touching the floor showing how low the whole mount is. The angle is different as the Willys had two 45* bends in the toe board to firewall where the donor has three 30* ones.
Looked at modifying the originals a lot to fit but thought it would be better just to start from scratch. First need to workout how far back I need to go to get the bottom of the mount level with the bottom of the floor while still being behind that lip. You might noticed too that the second fold is down on an angle. That is because the donor firewall is not flat straight across like the Willys was. I wanted the lower part to still be like that. I had to continue down the firewall until the lower part was vertical and square.