what do do to my stock 5.3
 

hello i have a 2005 silverado single cab 4x4 with the 5.3 its stock other then an airaid cai and a bully dog programmer (which i want to get a costom tune instead) i just bought some flowmaster mufflers that i havent installed yet and i plan to get some long tubes later on but i wanted to see if theres anything else that would get me a lil more tq and hp without really going into the motor. thanks for reading and any feedback is appreciated.

Start with a good custom tune for your truck. You'll be impressed with the performance improvement over a canned generic tune. I was. Then as you add other performance improvements, have the tune edited / modified to optimize fuel/air and timing. Tuned performance from a stock trans is an appreciable improvement too.

thanks for the reply!! yeah thats what i am thinking on doing going with the costom tune after i install the flowmasters.. i also need to rebuild my rear end i have 3.42s that are not helping me at all

Torque converter and gears

Headers and then tune.