Side Exit Exhaust--Is there Room?

These are usually done on one side of the vehicle and exit the same side at the rear. The problem your facing is the actual Real estate available under the car to where you could place the muffler and still have ground clearance. The only place this could possibly fit would be at the rear of the trans tail shaft and I’m gonna tell ya you don’t have the room. Your best bet for side exiting exhaust is to mimic the AAR Cuda exhaust. You can purchase mandrel bent pipes and/or cut you’d own, then use this muffler;
Dynomax Performance 17676 Dynomax Super Turbo Mufflers | Summit Racing

You could also create your own muffler with the right metal and a mig welder. Just use header collectors welded to the muffler wall. Create your own inside path.

I also do agree and X pipe would be excellent to use.

Is your engine a slant 6?