When you add the stock leafs, you may have to grind off spring holders/nubs from them -- . A four-inch grinder with a cut-off wheel works well for this. Make sure to retain the nylon pieces that go in the ends to keep the squeaking to a minimum.

On the Calmini packs, they have those spring retainers to keep the leafs from fanning (they're visible in your second pic). Keep those, but remove the bolt for clearance.

An easy way to assemble your new leaf spring jigsaw puzzle is to pick up a long piece of all-thread and some nuts and washers. Use this and a pair of c-clamps to assemble the pack. Once together, remove the all-thread, insert the center pin and cut off excess. Mitch had this idea when we assembled my pack and it made it so much easier.

Hit the pack with some black spray paint and you'll be good to go.

If you don't have a good local source for u-bolts and center pins, go to foothilloffroad.com. They have the stuff cheap and have been nice people to deal with.

Hope this helps.