Well, you could buy a Swinger with a slant six in 69, or any combo, but the sales brochures showed the differences. "Swinger 340" was definately a package car. The others are "Swingers" with 340's, or slants or 318's...
The Dart option book shows a lot of interesting codes, and option packages. I bought the book off e-bay, and was suprised with what it showed. Some guy told me that my car should not have the basic bench seat with carpet, but with rubber floor mats. The book showed that ALL 4 spds had carpet. Lots of tidbits like that, which I never knew.And Vitamin -C, that car isn't chickish, I wish I had some of those options.