3.31 or 3.55

My 3:55's put me at about 3000 rpm at 60 mph with a 25 inch tire and a 4 speed. Don't have much use for 4th gear in the city as was previously stated. I had 3:23 open diff previously and she still pulled nice and strong once the tire stopped spinning. I would like to try a 3:23 sure grip.