8 3/4 Sure Grip ratio change

I have a resto-modded 67 Barracuda with a built small block in it. The car currently has a built 727 with a 8 3/4 Sure-Grip with 3.23 gears. I'd like to do a 4-speed swap but that's out of question as she loves the car as it is. So I am thinking about a lower gear ratio (she will never know Ha Ha).

The car is used for local car shows and going out to dinner, etc. A few shows might be 30 miles away, most are 10 or so here in Northern WI. What would be a good swap for harder acceleration and keeping the small block revving?