Well a week ago i bought a 2004 Silverado 1500 Extended Cab 5.3L Automatic 4wd.

Mods:
17" Pro Comp Alloy's
6" Bazooka Box
K&N Drop in Filter
4" Lift from Lift Kit Warehouse (awaiting invoice for exact brand)
Exhaust removed and a 3" Dump was installed just after the OEM collector
Superchips FlashPaq Programmer

Opinions:
Programmer: This was much less awesome then i thought it would be. I've only run the 87 Octane file so far, but as soon as this tank if empty i'll throw in some 91 and give it a real test.

Exhaust: It is awesome. Not insane loud, but definitly not quiet.

Lift: It sounds like i'm running over sticks everytime i start moving forward or backwards. I have no idea what it is, but it's bugging me. Any ideas?

Bazooka Box: Fit's perfect under the read bench seat. Decent sound and i cna still throw tools on it.