The only problem with that method is that you make an assumption that the stab is mounted correctly in relationship to the thrust-line of the aircraft. It sounds like RhyanO is trying to determine if the stab and wing are in fact mounted at the proper angles in relationship to the thrust-line. The vast majority of sport aircraft have the horizontal stab zeroed with the thrust-line, but you really need the plans to know for certain. A phone call to Horizon or the manufacturer may be necessary if that information didn't come with the plane.