If I remember correctly, the regular Crossfire doesn't have a resonator before the muffler, but it does have a Y-pipe immediately after the cats, making the duel exhaust into a single, then it goes to the muffler.
I could be wrong, it might have a resonator, but if it does, its only a single in/out version.

The SRT on the other hand, has a true duel set up going from the cats to the resonator...then it exits the resonator with a bigger single pipe that connects to the muffler. So the SRT resonator acts like the Y-pipe.

The Borla system added a resonator just like the SRT except it has only one inlet pipe that connects to the factory Y-pipe of the regular Crossfire.