I agree with most people here that say loudness alone doesn't earn respect. If you hear a bigger cam and can tell it's geared and has a high stall converter on an auto, then you have to give it a little respect. I think 5.0 Mustangs sound really good with Flowmasters and 2.5" exhaust, it's just that EVERYONE has that. I have full length headers, 2.5" pipes, and cheap Thrush glasspacks on my car with 3" chrome 45 degree tips. It's loud, but at an idle, it sounds awesome. It's not too loud, the idle is actually fairly quiet, it rumbles, and has a very deep tone. When you step on it and hit about 3500 RsPM then it gets a little louder, but not obnoxiously loud. I'd say it's in the middle third of the loudness scale. At the very top of the middle third though.
