I can tell you from experience that a 3.38 to 1 would be better than a 3.08 to 1 with your tire height and a stock 3 speed. The 3.08 will not get you out of shallow hole with a medium sized load in the bed. You would be able to go 70 all day long with the 3.08, but there is no such thing as free lunch.
Carl


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission