Shocks!
I've always thought that the block in the rear are for the leaf springs to have a flat, level spot to be attached to. I'd heard bilsteins were the way, and they have that application for 0-2 inch adjustablity. Does anyone know how much they run?
I used to think that too til' I educated myself on them. You don't HAVE to have the blocks there and as far as the Bilsteins go, I've seen them in the range of $400-$1200.
I'm not actually sure what the blocks do but I was watching Trucks on the Speed channel and instead of using the blocks they put more leeafsprings and used Bilstein shocks and rated it as a 50% better ride with the 8" lift on it.
200-400 for a set of Bilsteins is quite far....keep in mind though, you can have bilstein custom valve any set of shocks. Talk to their tech guys and they can recommend whatever jounce and rebound settings that will be appropriate.

