Something different Building for MPG.

Well I put the 3.9 with the A500 overdrive & 3.55 posi in my 1966 Dart wagon and the best mileage I can get is 22 mpg at 80 miles per hour that is where it likes to cruise. I drive about 75 miles round trip and is most on the freeway. I guess one of these days I will cruie at 65 and see what it gets with the cruise control set.