One of the things I have always said about this is... Unless you knew your car from new its hard to tell which one your car came with. From what I have been able to tell it all comes down to whether or not your carbs had a center bowl vent from the factory. There are too many unknowns on this one and until we find some kind of paper trail or a time line for a change that occured its a personal call for the person restoring his/her car.