Weren't teh late Feather Dusters and Dart Lites rated at 36mpg highway with the /6 and A833OD?

That would be a considerable jump above what my 72 Swinger with a /6 and A904 got, about double. I know there was a bit more than just the trans swap invovled, but even half that improvement would put me int eh mid-upper 20's.