I have a true dual set-up with 2.5" stainless, hi flow cats, H pipe, Magnaflow resonators and 13" Borlas, new style gas tank in an '89 automatic sc. I tried it without the resonators and it was loud. Since my car is an automatic, the x-pipe would have blocked access to the tranny with resonators so I compromised.
X pipe might work in a stick car.