...update:

All 4 leaf springs are replaced, and a correction - ProComp leafs are not covered under a lifetime warranty, but 4WP did hook me up and honored their original stance. While I had it all apart I replaced the bump stops with ones much better suited for this truck. The first try were simply 'big' Jeep bumps that really just checked the box but did not really work that great. Plus the rust has eroded the 'capture' between the rubber and steel base. I found these big 4-bolt uber bump stops from Energy Suspension, pn 90.6006G for a medium duty truck. To make things as simple as possible I ditched the 3/8" u-bolt plates and made my own from 1/2" plate. Then I fabbed up 16 thick DOM spacers, and after hogging out the polyurethane everything bolted up nice and clean, and these will actually 'work'.

bottle of my favorite beer for reference -


old slightly warped 3/8" plates and new home-brewed 1/2" plates -


a fresh wood rotary rasp does a fantastic job of 'shaping polyurethane -


DOM insert/spacer/inserts in place -




3/16 steel strap capture both the DOM spacers and bump stops nicely -
Fronts -


Rears (ran out of room for the extra washer, and I'll correct for this with new u-bolts when I get a chance... -