x and h pipes

I would disagree with that statement. I wnet from 2.25" dual exhaust with straight through glass pak mufflers to a 2.5" system with an x-pipe and Flowmaster mufflers.

By the butt dyno I did not feel any difference in power but the sound level is low at cruise with no interior resonance. This is an ~ 370 HP 360.

I just can't see a 20-25 ft-lb increase in torque by just adding the x-pipe.