Your engine doesn't have enough compression for the deep throaty sounds of a V8, so don't compare V8 sounds and mufflers to a inline 6. Dual pipes will not make a performance difference, a little sound change is about all they do. Also pipe size matters, 2" would be maximum for a single exhaust system. Placing the muffler back at the axle will give a deeper tone and less ( rap rap ) then placing the muffler under the cab, it's long tail pipes give the inline six its distinctive sound.
Joe
