I see 30* above outside air temp for iat2 when cruising. Not sure what iat1 is I never pay attention to that. I saw an increase in iat2 when I went from a pullied eaton to a gen 1 tvs, I don't recall the exact number any more, think it was a 5* to 10* increase. Your plugs probably need to be gapped tighter, I would go to a regular copper TR6 gapped at .028.