OK, I just checked and I don't have your operating system defined otherwise I would change these for you and let you go from there.
You're either going to need to contact Will - minigeist website if you google it or Dave - DStek. You'll need to have the following background tables changed over to the 6.2's TB settings and then you'll need to change the TB setting in the main cal that you have accessible to the same value. Make sure the manifold volume is right for the 6.2's too - I glanced and it might have been. Then you can re-tune everything from there. That will fix your return to idle issues, decel issues and touchy pedal that having these wrong causes. I'm actually tuning one right now with the same setup, so grabbed the pics from it minus it having a different cam.
The tables you'll need to request are the "throttle area" and the "etc max" scaler table. The rate table is the same as the area table in the pic. Ask for them to put them into your cal using the 6.2 truck settings.
Throttle Tables.jpg