This info can be found in the performance catolog. But in short, in America, the following is how it goes. Not all models are included here;
A body. Small compacts of the day. Basic, inexpensive transportation. Dart, Scamp, Demon, Duster Valiant.
B body. Mid size vehicals that also come in 4 doors on some models. Family sedans and pereformance sedans. Road runner, GTX line Charger , Super bee, Cornet, Cordoba, Magnum
C body. Full size cars. Upper scaled. Some model names were also B bodys.
D body were the masive cars. Imperials were in this line.
E body. 1970 - 1974 Barracuda and Challenger.
F body Volare, Aspen
J body, 80 - 83 Cordoba Mirada
M body, Diplomat, LeBaron Gran Fury
R body, New Yorker, St. Regis