I'm looking at getting a '64 chevy, 250 6cyl, 4 on the floor for going out on weekends and things. I know it won't get great gas mileage but it should be better than my '68 Plymouth with a cammed up 383. What should kind of mpg should it get? I'm not sure about the rear end gear ratio, but I'm guessing its around the upper 3's or low 4's for towing and hauling power. Thanks for any replies.