We bought a used GT out of Texas. It runs great! In fact, the way it runs and shifts I have a strong suspicion that the engine and trans are tuned. I am a complete virgin when it comes to this topic. My scanner shows OEM calibration, but I'm sure that can be faked in a tune. How do I find out what possible specs this is tuned to? Can a tuner plug into it and determine what it has? It seems to run fine on 87 octane fuel but......?