my reply wasn't meant to be obnoxious but based on my experience with low gears. i had a 383 4spd car i ran around on for a short while with 4.30's or 4.56, don't remember exactly but pretty sure it was only getting around 6 in town. my stock 440 r/t with 3.23's and a fairly good tune probably gets about 10 in town. these old dinosaurs are just inefficiently thirsty. one thing for sure is if mpg and a clean burn are important it's fairly difficult beat a stock avs carb.