GDE can correct me here, but I think their curves are based on simple correct data being input from the BCM on wheel speed, etc, so if you have larger tires/gears/etc, then as long as you re-calibrate the BCM, then the GDE tune should function the same way. Of course you're going to loose efficiency, but the tune will still be doing the best it can with what it has.
Dan
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2005 Silver CRD Limited

245/75R16 GoodYear Duratracs
Fumoto drain | ProVent CCV Filter
Stanadyne FM100 filter | Cummins fuel pump
GDE Eco | SEGR | BoulderBars | FrankenLift | Frankenskids