[67C10Step]

Oh, I see it now. That is a bit odd. You will need to check your measurements between the hold down strips on the bed sides. I copied the below from another post about bed dimensions:

Inside height of bed (to top of bed) = 19 1/2 inches; Inside length = 78 1/4 (SWB) and 98 inches (LWB); Width of bed = 66 inches; width between wheel houses = 50 inches. From the diagram, it seems that the distance between uprights, when the tailgate is open, is the 66-inch measurement.

Also, I made sure my bed was square by measuring diagonally about a dozen times and adjusting until I was less than 1/16" difference. Then I laid out all my wood with the hold down strips. Adjusted them side to side and front to back until I was happy with all my gaps. Marked the side pieces for holes by scribing through the hold down strips on the bed sides. Numbered the bed strips from left to right so I'd put them back in the exact locations. The ones with the actual bed to frame mount bolts were an issue but the middle pieces I wanted to make sure they went back where I laid them out.

Now, as to how to fix the bow in the bed side, I will leave that to a much better body person that I am.