Help! I've been searching and reading posts on this forum and others about programmers for 12' - 13' for days. It doesn't seem as though there is one product that clearly outperforms others. The Bully Dog sounds promising. It claims to facilitate the use of lockers and swaybar disco in 4hi but, no one has confirmed this yet. There's also quite a bit of criticism regarding the software and throttle programming. None appear to address automatics trany shifting issues that arise with larger tires. What I need at minimum is the ability to change the tire size to 35s and gear ratio to 4.56. Most should do that. I'd like to hear more feedback from people who are using these things on 12' and up with the Pentastar motor and automatics transmission, the good, the bad, and the ugly.