I think your springs are binding from lack of "lubrication" or the accumulation of dirt and rust. It makes it feel like a solid suspension that way. The only way it feels better is when they're loaded up. I built a 1 ton chassis for a fellow 'Bolter and we bought some stuff made specifically for leaf springs. It called something like "Slip-Plate" or so. It's paint impregnated with graphite to prevent binding. He hasn't finished the truck yet so I can't comment on how well it worked. It's something to consider when you redo your springs,
Scott
