MPG The Best Of Both Worlds

Set your timing as advanced as you can without spark knock, and as someone mentioned earlier use the vacuum advance on your distributor. A good spreadbore type carburetor would likely help a lot too (vacuum operated secondaries). Simple things like a front end alignment, good radial tires inflated to the correct pressure, and a good tune-up will make a difference when it comes to saving gas. If you presently have a hood scoop on the car, make it fully functional or remove it as it becomes a huge source of drag.