Again...
70-74 HP Challengers had badges that said "Four Barrel"- 440, 383, 340, 360.
71-74 HP Chargers had badges that were the same style but larger and said "Magnum"- 440, 383, 340, 360.
Super easy to prove.
I also misspoke when I said 340 Darts, Demons and Dart Sports had Magnum badges.
AFAIK they only had "340" badges.