An X-pipe will remove the typical 'stereo' exhaust pulses coming from the tubes. It will sound more like a modern V8-car.
The H-pipe retains some of that 'old' V8 muscle car sound better imo.
Agreed - I just like the way an H-pipe sounds better than an X. Stu, as far as textbook "proper" diameter, 2" would be optimum for the crossover. However, since you already have a crossover, I don't think it would be worth the time & trouble to change that out. Might make no difference at all from a performance standpoint.
