Flowmaster 10
 

Here's how a flow master series 10 sounds like on a 12 JK

12 Jeep Wrangler Exhaust - YouTube

I dont know if thats with or without the resonator but thats fairly crappy sounding to me

Oh i know it wont sound like a race car...thats just what they are made for. And they dont help a race car sound like race car...they are just enough muffler for cars that race at drag strips that require mufflers.

On the last TJ I had I put in a 2.5" high flow cat, all 2.5" pipe, flowmaster before the rear axle, 3" rear pipe and dumped it facing down just inches behind the rear axle, it was definitely the best sounding Jeep (6cyl) I ever heard, I plan on doing something similar on my 12, upsize the pipe after the cats, true duals (if possible), flowmaster(s), and some 3" pipe dumping just over the rear axle (facing down). The shorter the total length the louder and racier it will sound, the larger the pipe the lower the sound (and obviously the muffler impacts it a lot).

The muffler shop charged me less because I was using less pipe and it was about half the price of a catback system.

Not only would it sound nothing like you inline 6cyl jeep...true duals will actually be a serious pain with trying to fabricate it and if all the tests are right you will lose a great amoun of the trq curve by losing the balancing tube in the exhuast...ie the doughnut

Also go to big on the pipe and you are just wasting money