The '71 & '72 model years have a twist.
Until the end of the 1970 model year, the typical model year ran from August 1st to July 31.
For the 1972 model year they started earlier, approximately the 2nd week of July & went over & beyond a typical model year rage at least a week into the 'second' August.
So 14 months involved instead of the former 12.
