Well, first off, you know there's no such thing as a 1968 Plymouth Volare. Volares were around from 1976 to 1980. So I'd suggest you start by finding a better vin decoder. The only difference between an Aspen hood and a Volare hood is the nameplates and trim on it. The hoods themselves are really the same. The model year of your car will be the sixth digit of the VIN. If it's a Volare the VIN will start with an "H" if it's an Aspen it will start with an "N".