A or B body??

The 71 Dart is an A-body. To confuse matters further, the 60-61 Dart would be considered a C-body, the 62 Dart is a B-Body, and the 63-76 Darts are A-bodies. Chrysler came up with the A-B-C designations in 1965. The A-body was the compact car platform, the B-body the intermediate, and C-body for the full-size. The A-body nomenclature was made retroactive to the 63 models, B-bodies to the 62s.

Things got more complicated later on as Chrysler issued a plethora of platforms and the letter nomenclature became less logical. It still exists today, though the platforms have a 2 letter nomenclature.