I'm going to have true duels put on my Chevy truck (350 Vortec) and I am stuck between the 50 Series Delta Flow50 Series Delta Flow and the new Super 40 Super 40 . Anyone installed or purchased a Super 40? If so what's your thoughts. I don't want it too loud on the inside, that's whyI want the 50 Series Delta Flow, rather than a 40 series. I've heard true duels with 40 series on a 83 Mustang (5.0L V8) and it was too loud for me. I want a deep rumble and good sound on accelleration but not it droning away at me while i'm driving, whether it be interstate or city. Any suggestions?