I had a Garmin G5 AI installed last week and the avionics shop seems to have difficulty in adjusting the pitch. The latest attempt (today) resulted in the AI displaying a 5 degree climb while in level flight. The roll calibration seems to be spot on. The installation manual discusses a panel offset. Does anyone know what that should be for a Cherokee? I don't understand why pilots can adjust pitch on the G5 with the experimental version but certified version does not permit adjustment.