[frizzen]

This looks like it'll be a very cool build to watch!

It's very easy to add extra helper-springs to the packs, with a little plier or file work you can wrap a second main-leaf around the original main leaf spring. I believe there is some difference between 'semi' and 'hi-lift' leaf springs, but that should let you have more options on getting it to behave just right.

If it's still not enough capacity with spring, there were a couple guys milling 'Walking Beams' that look like a spring pack for the Heavy Haul trucks.

Another idea for safe carry, if i ever start my ALF project i've been thinking about making the step bumpers, rub rail, and all that into basically giant 'rock sliders'. So it becomes all structural frames around the bottom of the body bolted to the real frame