Hey Man... Welcome to the forum. I would start out with Cold Air Induction kit, Pulleys, Nelson Tune, Trans-Go Shift kit, Throttle Body Spacer. Later on you could look into stall converter, cam, and some type of forced induction. C-ya around....
2002 Red Chevy RCSS (engine mods)- 05 5.3L, Procharger P-1SC 9lb.pulley, 80mm BBK TB, TB By-Pass, 38lb. Inj., AlkyControl Meth Kit, ASM L/T's, Magnaflow X-pipe, Borla's, FLT Level 5 4L65e, PI 3000 Stall, B&M Tranny Cooler, 3:73's, G-80, E-Fans, 160' Thermo. Custom Built Intake with K&N. WideBand 02 Sensor, DIXIE TUNED.