75/76 Dodge Dart /6 average MPG and improvements

I should probably give a little bit more back ground. I live in an area where Im centrally and very closely located to work, grocers and any other necessities. Im aware that there will be days, maybe even weeks that this car will sit getting fixed up, and thats not such an issue. And when it comes down to it, I have a (new) car I can borrow. This whole classic car daily driver idea stems from a basic interest in learning to do my own work on cars and further my knowledge in that as a hobby. the dart it self, as I said, is chosen based on the fact that it would be incredibly unrealistic to buy, work on and insure (daily or collectors insurance) that I also have to dump a ton of money into gas as well. Honestly, my first pick in car would have been a 68 Cadillac Fleetwood (feel in love with that one when I was knee high to a grasshopper) were daily practicality not an issue. Or a 78/79 Bronco. Or if I was really really keen on muscle cars and still unencumbered by budgets, probably something like the AMC Rebel. But as it stands, I have to mix my want for a really cool car with my need for practicality. As I stated in my original post, the Dart seems like a really good middle ground, and with less concern for authenticity, seems like it has the potential to be made practical, even almost practical by today standards. But thats just what I figure. Your all the experts, so keep the advice and thoughts coming. :)