H or X CROSSOVER?

I ran the dr gas x pipe on two different big blocks for over 20 years. Loved it. Unfortunately it was on my Polara when I sold it. I wish they were still in business.
When I did my Duster I used a Magnaflow tru x and the Borla Pro XS mufflers. I have to say it is fairly quiet until you hammer it.I have 2" TTi headers with 3" pipe through the x pipe then reduces to 2.5 with the Flowmaster tapered reducers and 2.5 out the back.