I just bought a 2005 5.4 F350. That engine needs to kick down a lot to keep the truck moving with even slight hills. I don't mind, but the exhaust is loud - pretty much have to yell to be heard by the passenger. The dealership seems to think that is normal for that combo of engine and body. They did replace one of the headers before I picked it up, but said nothing was wrong with muffler or exhaust pipe. Is that normal? Anyone out there with the same experience with this kind of vehicle?