In my 54 car with a 235, t-5 with the .82 overdrive( I think that is right, it's not the .73), and 205/75/15 tires, and 3.08 rear end gears I am getting at least 20 mpg running at 70-75 mph. I'm running Tom Langdons dual carb set up on a fenton intake with a set of Fenton headers. Something sounds wrong with only getting approx. 10mpg. Even when I still had the three speed with a tired motor I was getting 18-20 hammering it down the highway.
