RE: how to set/check engine thrust angle
.838" 12" from the centerline of the engine? That sounds like way too much. Double check your math, you may have missplaced the decimel.
edit: Well it's not the math using the figures you gave my calculator comes up with the same number. Just sounds like way too much, that's over 3/4 of an inch. Just guessing I would think it would be more like .1"-.2", but that is just a wild guess.