Not a mopar, but I have a car that gets 20mpg with a 355/4spd, 28" tires, 3.73, no overdrive. Burns 91oct pump gas, even has a Edelbrock 600 carb. With a Powershot plate, it's been 5.73 in the 1/8th with a 1.30 60'. Pretty sure it would run 8's at a 1/4mi track, but don't want to jump thru all the hoops for the tech guys :)
Grant