Take a look in the HPTuners tune repository. Work the VE and MAF tables to get your fuel trims to +-5, play with timing a bit as its very low stock just dont go crazy if you plan to tow. You can play with PE enable modifiers so that it will hit PE a bit sooner, stock thresholds are pretty high so you can bring PE in a bit sooner. Depends how crazy you want to get.
14 Sierra, 5.3 6spd, All Terrain CCSB. Daily
04 Sierra Denali AWD TVS2300@15psi on top of 8 Pistons, Leftcoast32 8 Rib setup, Precision Built 4L80E, PI 2800, custom 4" exhaust, Tuned by Myself