I believe that chart is incorrect or misleading. I can't find it now, but I'd found a different version of this chart that noted the '73 cars as 2240xxx. My car was manufactured on April 10, 1973 - it is a 1973 model - and the VIN is 2240723. Just 175 cars before yours. It makes sense that yours was built 2 months later in June of 1973.