My SPF had a 402 Roush with advertised 420 HP - running straight 2.25" exhaust front to back and it was LOUD and didn't have that pleasing of a tone when you put your foot into it. Sounded cool at idle and low put-putting around a parking lot, but if you shared the highway with it it was unpleasant.
https://www.youtube.com/watch?v=j0Gm...ature=youtu.be