Apache Kid,
Interesting solution! I'm not sure my main springs and overload springs have the same curvature though.
I'd like to keep the ride soft... er at least somewhat soft when I'm not carrying a load. I can do this best by only running on the main springs. When I am carrying a load, that's when I want the overload springs to engage and give some extra support.
With the setup I have (or should I say intend to restore it to), the overload springs only engage when carrying a heavy load.
I wonder how hard / bumpy the ride would be with the 8 main springs and 6 overload springs (all 2 1/2" wide) all engaged at once and no load on the back. WEEEEEEE Bouncy Bouncy Bouncy!