70 dart R/T???

Guess you've never seen a car with the California noise abatement package on it huh? Ever seen a V code Six Pack Challenger without tips? Or a Cuda? Yep, the environazis were at work even way back then. Republik of Kalifornia cars didn't have tips. Just turn downs to help cut noise.

And yeah, I've seen order numbers with Alpha characters in them. None with an "M" though
Are you saying those cars would have both codes and the tips would be in the trunk or something? I have never seen a car with both codes. Of course, that doesn't mean there were none. Yes, there are cars with alpha numbers but no A Bodies with an "M". As far as I know the only cars with an "M" in the VON were AAR Cudas.