Over the years I've found front left hand nuts on BOTH sides, on cars that had never seen service. So apparently sold that way from the factory. One CA Pantera had a pushbutton (removable) right spindle while the left side was the later integral forging type.
When L models came out in late '72, left hand threaded spindles disappeared while the stub axles always had lefties- also occasionally interchanged side to side. So given the mileage these cars get nowadays, it seems not to matter much.