Put on a new muffler today. I had some extra sheet metal laying around, so I went at it and made myself a new one. Single in/single out. its 8" x 4" x 20". Turns out my entire cat-back is 2-3/4" after I thought it was 2-1/2" Anyway, all I did on the interior was put two angled baffles and nothing else. It sounds pretty good, a little deeper than the stock one but a little louder too. Going to try and get some sound clips in a few days.