When I brought my truck in for the mileage flash (it worked by the way) the tech was checking out my gauge, AFE PG7 w/torque tube, and BD short shift. All he said was "sweet, I like the turbo whistle". I asked him about warranty stuff with these things installed on it and he basicly said what Tommeygun said in an earlier post. The only part on my truck that isn't warranted in the exhaust manifold (drilled and tapped) and the trans... but that's only if the shorty kit were to cause a failure (not likely). My advice is to find a dealership service department with some common sense. Up here in Anchorage, only 1 of the 2 falls into this category.
Bert
Bert