The Pypes Race Pros are on the 67- 3" with an x-pipe. I did their whole kit, but modified the tailpipes to dump behind the rear wheel because the cannons going straight out was hideous.
The Magnaflow cat back kit is on my 02 Silverado 2500HD 6.0L with JBA shorty headers and factory cats. That muffler is a 2-3" in, 1-4" out configuration.
Lastly, the Pig has the 2.5" Borla with self made exhaust from a mandrel bent Speedway kit. I had to add a resonator to quiet it down. It's still not what I want, but it'll do.
So, to answer you question: I think my truck sounds the best with the Olds as a close second. However, as you can see, it's an apples to oranges to bananas comparison.......
