Actually, it is the opposite. We have had too many cars to name on both my AWD DynoJet and Brian's and assuming he uses "SAE" like we do his typically reads slightly higher. Neither is right or wrong, but the cars that have dynoed on both over the years have supported this over and over and over again.
There is no "Fair" in this. Chris' car was bone-stock so how good or bad his numbers are comparesd to another "SS" is a Ford thing, not a tuner or shop thing.
Jeff