i'm only 5'6" but a wide body, channeled my '33 5 window 5", sectioned it 5.5" .... tapered the floors from flush at the seat's front to a 2" drop at the seat back... looks tight but nice when in...
Measure between the door hinges on an uncut Model A coupe: From the bottom hinge to the middle hinge is 10 3/4 inches. from the middle hinge to the top hinge is 15 3/4 inches. Therefore, if you plan to use three hinges, 5 inches is the perfect chop. IMO