I have a 2005 silverado 2wheel drive with a 5.3l, 3.73's, cai, throttlebody spacer, msd wires, lt headers, no cat's, with 3'' flowmaster exhaust, comp cams 208/212 .554/.558 on a 115lsa, 1.75 roller rockers, and a custom tune. I have good mid and upper power. However, my truck def lacks it in the pants when in comes to take off. I haven't had my tune updated since the cam. I'll be getting that done soon, so I hope that will help. Anyone have any sugestions, or am I only looking at gears? I am rolling on 285/50/20's and I can barley chrip them on a hard take off.