I have messed around an messed around trying to get the speedometer to calibrate out with zero luck it shows around 30mph @6moh an 110 @ 60. I now it has to be something in the calibration files being different because of the way a vette reads off the reluctor ring of the differential compared to the trans shaft an Ive tried everything I can thin of in comparison to a truck file an nothing works. Anyone got an answer for this.