I think you'd notice a bigger improvement going from 3.23 to 3.73s... But depending on the stall you use, that might be too much.

I wanted to maintain MAX fuel mileage in my setup...

I went from 20 MPG w/ 2.73s

to 18.5 MPG w/ 3.42s

 

The most i can go with and remain legal in my class is 3.42's. That's why I'm not so sure it's worth it.