15.0 mpg to 21.6 mpg!

What kind of numbers? My 273 4 speed gets right at 20 hwy. if I drive it like a grandpa. I have a o/d 833 that could improve things.
It is actually a built 360. The car has no stripes,mags or scoops. Looks like a grandpa's car. 360, 4 speed and a 460 lift cam and 222 duration a .050. 3.23 with 26 inch tire and sure grip. still needs more tire. at about 70 mph at about 3200 rpm getting 16 mpg. around town less, only because my foot is in it all the time.:rolleyes: And a/c blowing cold.