Difference between 3:55 and 3:23 gears

I am presently running 3:55 gears with 24 in tall tires. At 60 MPH the car is revving at 3100 RPM's. I have a set of 3:23 gears in another pot and was wondering what difference I would see with a gear change. We are looking at a trip next summer and I was wondering if it would be worth my while to change gears ?