How can I get more HP and torque on a 2005 Chevy Silverado z71 crew cab
Cold air induction. Exhaust system. Get the ECU reprogrammed. Start there.
If you don't care about fuel mileage and going fast, change the front and rear gear ratios to something really low, 4.10's will make a puller out of it, or you can really get down there with some 4.56's or some 4.73's. that'll pull your stumps and your plow. Just don't plan on getting anywhere very fast.
Better breathing is a must. Larger and less restricted intake, and larger and less restricted exhaust. Check the on line test results. 15 to 25 HP gain and torque along with mileage. There are low restrictive cats that also can be used. If you really feel the need for speed, look at turbo charging. There are ones that hook up in the rear of the vehicle and the return lines cool the air so less problem of hot air reaching the intake. For all that money, ten grand will get you a huge stump-pulling crate motor. Start with the exhaust and intake air flow and a reprogrammed chip.
Buy a supercharger kit.
Looking for a Used Silverado 1500 in your area?
CarGurus has 143,996 nationwide Silverado 1500 listings starting at $1,995.
Search Chevrolet Silverado 1500 Questions
Chevrolet Silverado 1500 Experts