If your combo needs to have a higher RPM to effectively fill the cylinders then going to a numerically lower gear could actually worsen your gas mileage.
If your combo is relatively stock then you would probably be happy with 2.75-1 or 3.00-1 gears, an open diff would not hurt either.
53 F100, Volare clip, 4 wheel disc 390-wide ratio toploader
![[linked image]](../../../../../../webpages.charter.net/hotrods/truck1.jpg)
