Depending what you're after, I may have another solution.
On my '80 LeBaron, I had headers, header glass packs and about 3 foot of 2.5" exhaust tube on each side. Just enough to come out of the glass pack, turn 45* and run to the same spot that AAR's and T/A's exit.
It was LOUD, though. I was running 55-65 mph one time and passed an approaching trooper. After he went past, he wheeled around and lit me up. Turns out he had his CB, radio, A/C all on with the windows up and couldn't hear anything when I went past.