I am cloning a 72 satellite. The car came with no headliner or mouldings. Also it only had 3 bows two at the front & one in the back. The car has factory holes for a 6 bow liner. My Mopar buddy has a complete set of 4 for me. Do I need a six bow system?? Or will a 4 bow system work even though the car has holes for 6???