i'm not looking for anything extreme, i just want more power throughout the entire rpm range. i have a lifted 03 Z71 5.3L. it has an intake, exhaust, shorty headers, throttle body spacer, granatelli mass air sensor, nology wires and plugs and superchips. some time this year i'm gonna change my gear ratio to 4.56 and be running 35'' tires. i'm running 33's and 3.73 gears for now. this is my dd and i tow and offroad on occasion.