I've got the system on my Dart Sport race car with Dynomax Ultraflow mufflers ending at the rear housing. The hangers bolt to the underside of the rear seat belt mounts. I think I would have room for down-turns. But I'm at work and can't double-checl or take pics today.

You should be able to cut back the ends of the x-pipe if the mufflers need to move back. Just gotta line up a straight piece of pipe for the hangers.