I'm running around with torsion bar crank and Boise spring works kit. I would recommend the springs over a shackle any day, especially if you haul stuff. With the backspacing of the wheels, the only rubbing I get is on the drivers side at the back of the wheel well, but it is only when going fast over bumps and turning left. It almost never does it on the road. I don't really do what I would call off roading with this truck, but sometimes it does see dirt. If I keep the speed down to give the suspension time to cycle it doesn't rub. Here is my setup, copied from the readers rides thread:
Torsion bars turned up
Fullsize bumpstops GM Part # 15712438
Energy Suspension Polyurathane Sway Bar Bushings Part # 35207G
Boise Springworks spring kit
Bilstein shocks Part #24-016810 and #24-014106
Pro Comp 15x8 with 5 inch backspacing steel wheels Part # 98-5861S5
Goodyear Authority A/T 31x10.5x15 tires
Moog upper control arm bushings Part # K6418
Energy Suspension lower control arm bushings Part # 3.3167g
Slight fender trimming
Cut front air dam
How it sits as of moments ago:
As far as running 33s with a body lift and skidz flairs, all I can say is that the fender cuts needed for the flairs is what's important, not the flairs themselves. I had to trim the corners of the front wheelwells, not to the extent that is needed for the flairs but it is trimmed.
On a side note, my truck rides and drives great, better than anything I've owned so far. It makes for a good dual purpose truck. It is currently at what I saw HJ call "the happy place".
Hope this is helpful, now get to wrenching! And don't forget the camera!