The OBDII port is what you're speaking about and is the most popular way to upgrade the trucks for sure. We stock the Superchips, Predator, and Bullydog programmers that use the OBDII port for uploading HP programs. You'll find they are the most popular, the Bully Dog even has a digital gauge package that plugs into the OBDII at all times to retreive the gauge info. Call us if you have any questions etc.
Mark @ DPPI