I've found out that the Titan is far more sensitive when it comes to interior noise levels. Especially the CC. The factory location of the muffler is right below the back edge of the cab where the gap between the bed and cab begins, not exactly an ideal placement. Most of the GM trucks have the muffler back under the actual bed. You can put a 2 chamber 40 series on and still have a civilized interior sound level. But due to the Titan CC's short bed and big cab, the muffler has to be placed where it is. I even noticed the difference between the interior noise on the KC and CC. I test drove a KC and hardley noticed the exhaust. I didn't test drive a CC till the day I bought mine

and it is definately more noticible. Either way, this is a very subjective choice, and there is little we can do for eachother on a forum other than give empirical info.