I just installed a Magnaflow muffler on my 05 CCSB last week. Its a dual 2.5 inet/ 3in. single outlet and I ran it out to a Corsa Dual side exit tip and it looks and sounds great for a DD exaust. Its very deep with no crackle sounds mean under WOT, but very quite cruzin down the road.

I had Mags on my 02 silverado and HATED them, they crackled and popped sounded like straight pipes but that was with no cats and Long Tubes.

Hope you enjoy...