1968 Ford F100 - The Bumpside Build-Off

I was also anxious to check out all the new space underneath the floor I was gaining. The extra room below will be more useful to me than above since there is ample space for a gas tank, battery, air tanks, A/C components, etc.

The back edge of the bed floor by the tailgate was a bit of a struggle to free from the crossmembers underneath it, even after drilling the spot welds, so a little straightening was in order. A piece of heavy-wall rectangle tube was helpful to get in the corners of the ribs in the floor to straighten 'em out.

For one reason or another, the rearmost crossbrace in my bed's floor was cracked in more than a few spots. It didn't look like the bed or the truck had been hit or used hard, which would be the cause for the cracks, and it still remains a mystery, but they were so rampant the two rear bed mounts almost cracked off the crossmember. I had to address this before going too much farther.

After spending a few hours trying to straighten out the crossmember and line the cracks back up so I could weld them up with the TIG welder, there were still too many for me to live with, along with the thought of any cracks coming back later. So I made some measurements, went to my local steel supply yard, and got a 20-foot piece of 3x2/.063-wall mild steel tubing. Welding two 6-foot pieces of the 3x2 together, I made a 3x4 crossmember, which wasn't quite as tall as the stock one, but it will work just fine when it's all said and done.

Before welding the new crossmember in place, I made sure the bedsides were still parallel to each other, as well as making sure the tailgate would still fit.

I used all the stock spot weld holes to weld the new crossmember in place to keep the factory looks going.

With the bed floor back in and the bed upside down, I began to line up the floor with the marks I made on the inner walls at the beginning. Here I'm pointing to how the inner walls were cut with the plasma cutter and where the floor used to be. I've also tacked the floor to the inner walls again using the factory spot weld holes.

With everything fairly well tack welded in place, but not fully welded, I double-checked the bed's dimensions with it back on the truck. It's important to rectify any discrepancies now before final welding. Notice the gap between the back edge of the bed floor and the last crossmember in the bed.

To support the rear of the bed floor, I cut another piece of the same 3x2 rectangle tubing to fit tight between the bedsides and clamped the floor to it. After making sure the piece of tubing was square side to side, I began welding the bed floor to it using the factory spot weld holes.