I had the magnaflow 5x8 oval 2.5 dual in 2.5 single out with the smallest case 14" (supposedly the loudest) part #12158 and to me its not even that loud the only thing that i dont care for is this kind of popping noise when at wide open throttle other than that i love it, i actually wish it was a little louder. mine is just a muffler replacement i have an 07 titan:cheers: