Someone say mods?

Not sure how much you can get out of the 2000 model (I'm asuming you have the 5.3 LS1 based engine), but if you're looking for a good, low buck with big bang performance mod.....just get a tune. Depending on who burns the PCM for you, you can get huge gains and power and gas milage too. Don't waste your money on cat backs or air intakes or just about any of the other bolt on crap out there. That is unless you want to pop on a turbo or super charger.