First off, Thanks Wally @ FTEDeisel. I recently installed stacks on my 6.7 and they were a touch on the obnoxious side as far as sound. So i talked to Wally about it and he recommended the Hushpower Muffler. Said it would take the edge off but leave a good sound. That is exactly what it did.
Here are a couple Pics of the muffler as i was installing it.
It is not a straight through design but you can still see right through it.
I also took some video of the truck before hand and after. First 2 parts of the video are with no muffler, last 2 are with the Hushpower. From this you should be able to hear a mild difference in sound, but from the cab almost all the interior drone is gone with the windows up, and it doesnt have that real loud top end like it did before. I would highly recommend this muffler to anybody who has the same issues as i was.:thumbsup
YouTube - Huspower Muffler on 6.7