If you have both pipes go into one glass pack it will sound better ,in my 2 cent opinion. Also larger pipes on the rice burners makes that sound I don't care for also. I have the fentons on my 302 GMC the dual pipes go into the muffler with dual inlets and dual outlets. I used the medium muffler from WALDRON'S EXHAUST. The pipe stops just after the back of the cab with turn down's.
http://waldronexhaust.com/shop/index.phpThey have videos on YOUTUBE. You can listen to many types of systems there.