I have a 59, 3100 with a fleet side box that was not assembled when I bought the truck. It came with a new front panel, and when I put it together the old Chevrolet tail gate that came with it seems seems too wide. Does anybody know what the factory 1959 fleet side tail gate width should have been. I am not sure if it is the wrong tail gate, the wrong / low quality front panel, or both, and I am not much of a restoration expert.
It looks like I have it backwards it measures 65-1/4 " between at the front between bed rails, and 64-3/4" at the back. cross sills are aftermarket too that came with the truck.
you just have to force the bed rails apart a bit. l had to do that to my truck when i restored it - this is not uncommon. loosen the fasteners that hold the sides to the sill, crossmember at the rear, and force the outsides apart. Then retighten. It may spring back so perhaps you have to push them apart a bit farther than the spacing you want to end up with. You don't have to move it much to get the results you need - only 1/4" on each side. you can use a porta-power (which you are unlikely to have) or a ratchet strap hooked to a tree, etc. This is a common way to make panels fit.
