Either find a good used set or preferably get new ones either OEM (pricey) or aftermarket but don't consider bandaids. You'll have a significant portion of the cost of replacements and the problem will still be there.
Im guessing you or the previous hauled some heavy loads.
New leafs, hangers possibly. And do not waste your money on OEM. Plenty of after market springs out there. Still not sure what dialogue you violated. Come on guys
What year and model of truck? Are you the original owner? Do you haul heavy items on a regular basis? Looks like heavy loads were put into that truck. If not you, then you can replace the leafs and mounts and rubber pads. I have seen the threads posted here. Lots of good companies out there.
On another note, if you consistently haul heavy things or tow heavy, upgrade your truck. Otherwise you are just wasting money.
1998 Dodge 3500/GaleBanks maxed out.
2015 Dodge 3500/Stock/Traveling truck