performance upgrades

hey i just bought an '05 gmc and was wondering what i could do to get some or a lot of horsepower and torque out of my 5.3 without buying a supercharger.

Put a new exhaust, new air intake and invest in a programmer ait'll be abot $800 to $1000 depending on the brands and were you go to buy them. I'll make a noticable change.