Spring Mounted Flatbed?'s

[Mikeb103]

I use color coded Die springs from McMaster Carr, I used the red https://www.mcmaster.com/9584k76(medium/heavy) rate in the rear and blue https://www.mcmaster.com/9573k73 (lighter) towards the front. I am going experiment with a gold https://www.mcmaster.com/9588k448 (stiffer) in place of the red on my next run. From the research I've done you want more stiffness towards the rear where it is rigidly mounted and progressively lighter towards the front.
The links give specs on rates, dimensions etc...

Sorry to resurrect an older thread but I’m in the process of building a flatbed for my F350 crew cab, and after busting a windshield from torsion it seems prudent to incorporate some flexibility, along the lines of what you did. Any long term lessons learned, things you wished you’d done differently? Thanks in advance