Part One: Rough In The Floor
The floor build began with the construction of the support bracing, which was MIG-welded together from 3/4x3/4x0.120-inch wall square steel tubing. The tubing was spaced 3/4 inch above the suspension bulkheads to provide as much room above without the worry of the floor hitting anything below. The bracing extends fore and aft, eventually contacting the factory inner bed walls for maximum support.
1. Once the floor area was measured, a 4x8-foot length of 18-gauge sheetmetal was cut in half using this pneumatic shear. The bed was too wide to build the floor out of one sheet, so two pieces turned sideways were necessary to fill the area. | 
2. An ESAB 110-volt plasma cutter on its highest setting was employed to make quick work of cutting out areas of the floor where the suspension would protrude and to cut the holes for our tool compartment and cooler. | 
3a. To join the front and back half of the floor together in the strongest and straightest manner, the Pullmax machine was used to punch a flange along the edges of the sheetmetal. The metal was fed through the machine as the tool reciprocated up and down, pressing the work piece between the two mandrels |
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3b. It took about 30 seconds to flange both pieces of steel, and once it was done, they slid right together and were ready to weld. Once the welds are ground down, you won't be able to tell the floor isn't one piece. | 
4. Here's a look at the floor so far and how the stock wheeltub fits into the picture. The tub will have to be lengthened at the base, but the width will work just fine. |
Part Two: Built-In Coolers!
1. With the floor roughed-in, it was time to build our storage compartments. Since raising the bed floor creates a fair amount of dead space underneath the tailgate, we figured what better way to use that space and build some nice sunken buckets to hold all of our stuff. To keep them looking nice and clean, as well as secure, the compartments will have lids fabricated so they're flush with the bed floor. | 
1a. First off, a bead roller was called upon to press channels into the sheetmetal to give it strength. | 
1b. By doing so, we won't have to build a support frame below the compartments, which will increase ground clearance and enable us to make the boxes even deeper. A sheetmetal brake was used to bend the flat metal into a U shape, which we could then weld shut on the ends |
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2a. The compartments are rectangle in shape, but we cut a half moon into the front edge so that the compartments would match the shape of the bed's rear fenderwells. | 
2b. That way, when you look from the side of the truck, you won't see the compartments behind the rear tires. |
3. The floor sheetmetal was removed from the bed, and then the compartments were MIG-welded into the bed bracing. | 
4a. Once the bracing and compartments were fully welded into the bed, the floor metal had a ton of strategically placed 3/16-inch holes punched into it so that the floor could be welded to the bracing. After the welds are ground down, the floor will be completely flat(4a, 4b, 4c) | 
4b. |
4c. | | |