We run a fleet of heavy equipment haulers in So Cal, worse freeways around. We've mounted centermatics on everything, and will continue to do so. As Geofkay stated to inspect truck for worn componets first, but these things are the bomb! Work excellent and have reduced premature tire swaps from cupping and chatter wear patterns.
You might take you rig to a frame and axle shop and have the springs checked? We have our springs built and balanced to each trucks weight. A good shop can weigh each corner of the truck and build the springs accordingly, as well customize the ride if your a fixed application as a toter/motor-coach.
I wouldnt get to crazy with shocks on a large truck with leaf suspension, NAPA sells and decent pair of Gaberials that work fine in the application, but let the frame shop match ya up with the correct configuration. Good Luck!