One thing you could do is adjust the auto-leveling sensor for your rearend to where it drops it down a couple of inches. A rear drop kit for free

If you serach around, theres a simple proceedure for this. Basically, you just loosen the sensor and move it up a few inches (or whatever).
Mines a 01 in Pewter. The only thing I have done is 20's on 305/50's. I had planned on a whole lot more, but I got married....and you know how that goes...
Hey, check this site out. Go through the pic forums. Man, theres more trucks wioth more mods then you and I both have money to spend on
http://www.fullsizechevy.com/forum/