Well hope you guys can help me out here, im planning on a new exhaust sytem for my challenger and i want you opinion/advice. I have a 383 four bbl stock with the HP cast iron manifolds. I plan either to run 2.5 or 3 inch stainless exhaust. Who can tell me the diffrence between mounting the mufflers before the rear end, and the sound diffrence after the rear next to the gas tank in stock possition.