Some years back I bought my daily driver. 1998 C3500. The P.O. went for the custom lowered look. He did that by torching the front springs and removing most of the leaves in the rear. I wanted an actual truck to use. So, i found new front springs (not easy.) And I air bagged the rear. It worked fine for hauling fifth wheels and such. After a while you deal with leaks, etc. I finally got tired of the ol' seasick, sway from side to side motion the bags gave me. The way it's plumbed, if your loaded, leaning to one side, the air goes to the unloaded side. Unless you have a side to side switch of some sort, there is no way to control that with a single pump or fill point. I found some low mile, original spring packs with overloads, and got rid of the bags. Much better ride now!!
Your first springs were probably way too soft with less than the stock number of leaves. Air bags are really only to adjust ride height. Mine are plumbed individually with individual fill points, so there's no air transfer between them and no sway. But of course I still have the stock springs with overload leave that engage on suspension compression. I do have to adjust them each time my load changes, but that's not a big deal - 3 or 4 times a year.
