To start off, I have a 2009 Tahoe with the 6.2 and it is 3.5" all the way out so I did not want to throw away a very efficient exhaust for a cat back, just wanted to change muffler. it does not use the same exhaust system as a Denali or Escalade probably due to the 2 speed transfer case and they made so few of them that no one makes a system for it.
I wanted to use a Magnaflow, but they do not make a 3.5" in offset-offset which my Tahoe requires.
My muffler guy suggested I try a Flowmaster Bigblock 50 Series which has the 3.5" with offset on both ends.
Well, I am not a Flowmaster fan at all and balked at the idea, but he convinced me to try it.
I really like the sound.. it sounds somewhat like my old Suburban with the big Block 454 engine and a cat back.. has some good sound when i get on it but at 75 on cruise it is completely quiet with the windows up and NO DRONE.. I still have the resonator and may leave it alone as I do not want to change the overall sound it has now.,
Pretty inexpensive way to get a good sound without spending a lot of money..
Good luck,
Thirdcoast