Any update? My take is that the tires are what makes the ride stiff or not, a stiffer vs a softer sidewall. Half of your suspension is in the tires' sidewall flex.... and being a 2500 it probably has 10 ply, load range E, tires which ride like bricks... try a set of regular 4 plys like you'd put on a half-ton. Also, the lower the profile of the tire, the worse they ride. The yellow Bilstein 4600 with the blue boot are the exact shocks that came with the Z71 RPO code from the factory. I have a 98 Z71 with replaced Bilsteins and 4-ply all-terrain tires, it rides great. In my experience.... softer shocks like ranchos suck, especially on the intestate at 80mph in the mountain passes, or even in town if you're a "spirited" driver on the street. They make your truck all floaty like a 76 Cadillac (not good for performance or towing/hauling in any way) and do very little dampening which would be super unsafe on the interstate if you were to ever tow with it. The Z71 RPO code only had three differences which make it a Z71.... the main feature being the geniune Bilstein shocks, an aluminum skid plate, and then the decals, that's it and that's all there was for a difference from non-Z71s.