Mopar Posi rear axle

Those imperial gallons are fine with me...i'm in Ontario!
Hard to believe 25mpg with a 426 Hemi
I know it sounds crazy, but loafing on the hiway at low RPM is the answer. Same as my 390. Can you imagine a Hemi with 3.55 gears, an OD transmission with .6 top gear and EFI? I get a vision of 30MPG and go like a raped ape.