How Rare? 1976 Dart Lite

As mentioned, I too think it would be interesting to see how economical you could make one go on the highway with modern mods as mentioned. I thought that Chrysler used some tweaks to the EGR system to extend total timing along with a Feather-Lite model only one barrel carb. The old EPA mileage rating document from 1976 did not identify the Feather-Lite models and showed the 225 manual trans Dart and Duster models to get 23 mpg highway. I wonder if some additional lightening and engine tweaks god get this car into the high 30s fuel economy.