67 Dodge Dart 273 - need gone asap

Appears to be an original Commando car as well. Whats the 5th digit in the VIN?

I also noticed on this car that it has a water shut-off valve in the heater hose circuit. The car doesn't appear to have (or had) A/C, so why the valve? My '67 Dart 273 doesn't have one. Just curious......