Rail top tool box install help

[refeicul]

I cam onto a pair of rail top box's but im trying to figure out how to install while keeping the full storage underneath. In other words i dont want supports that go to the bed or wheel wells. i dont even know if its possible without a wrack of some sort. which is how they where previously installed on the other truck.

Id love some further input

thanks for your help, Cheers!

 

[refeicul]

I was thinking of something like this.

Its similar to a truss rod in a guitar the red bit being a true angle iron, the blue bit square stock, the purple bit a threaded rod and the green bolts with one side welded to the rod the other bolt welded to the back plate.

the theory is that the rod provides tension to compensate for bend or flex in the square stock ie more tension = less flex.