Got a 5.3 LS, for a 99 Chevy Silverado 2500. I also have the PCM. A buddy of mine is also venturing down the same road, so I am hoping to pay it forward, with I what I learn here. I am looking forward to getting into the tuning part of things. I created my bench harness, used PCMHammer to create a bin file. Now I am looking for the appropriate XDF file. Can anyone point to the right path for that XDF? I will keep looking and reading. I appreciate the site and current and future help.