Best magnum MPG?

http://www.hughesengines.com/Index/...cyAmIFBsZW51bSBSZXBhaXIgS2l0cw==&partid=27091
fix intake mpg goes back up lol on efi.

my 68 valiant, sedan, 360 magnum, 2.47 close ratio 4 speed, 8 3/4 w power lok, 2.94 rear gear, gets 17mpg when I keep my foot out of it. 3310 750 holley vac secondary, hei module conversion, crosswind intake, stock motor, no cam, no valve springs. 14 inch rallye wheels. car would probably get 20+ with 15 tires and smaller carb