What difference in sound\performance does the length of the muffler make?? I ordered a complete exhaust system from Gibson a while back and they sent me the kit for the 6.7L Mega Cab, which I dont have so I sent it back and told them to just send me a muffler and their new 6" Tri-Flow tip(since they dont make a kit for the Quad Cab yet). I got the muffler in today and this muffler is much longer than the one that was in the mega cab system. Its like 30" long total. Is this the muffler I want??