1973 Swinger Trim Options?

First L is for Dart
the second L is low trim, M for medium and H for high
Unless something changed between 1970 and 73 LL is Dart Swinger and LH is a Dart Custom. Trim levels have nothing to do with engine size with one exception: in 1970 all the LM cars were 340 cars and only 340 cars - they had an odd mix of interior trim, like LH seats with LL door panels. I don't think there were any LM cars after 1970 because you had to buy a Demon to get a 340 (unless you lived north of the border).