Very impressed with gas mileage

Every one of these old cars is different, ignore the riff raff. I have a 318 Magnum out of a 95 pickup which I converted to carburetor, a 3-speed manual floor shift and an 8 1/4 with 2.71 gears in my 72 Valiant, driving 12 hours from Edmonton to Smithers BC I averaged 24 MPG.