The X pipe is from Dr Gas the rest is TTI. I ordered a cam and RHS cast iron X heads for the 408 in my truck from Brian at IMM and I asked if he had tested X pipes as I like the sound and wanted them on everything no matter how difficult they are to plumb correctly. I had mentioned my Dusters exhaust telling him I was considering stepping it up to 3" at the exit of the X and 3" all the way out and installing that X on my truck. Brian said there was power to be kept by not going 3" and leaving it as is on my car and getting new for the truck. Was he saving me work or keeping me from making the car worse IDK?