My wagon came factory with single,so we bent up a set of duals.
Most RWD Mopars had offset inlets and center outlets,IIRC.
The exception is of course your car since the cat convertors take up real estate underneath and the pipes are not as tight to the middle of the car compared to non-cat equipped cars.
The addition of the convertors changed the exhaust layout starting in 1975.
Dynomax Number 17747 is recommended.
Same muffler used on older B's without cat convertors.
It is not a "directional" flow muffler.
Made to fit many applications.
Just install it in the position required for your car.
Hope this helps.