Adding shorter gears will have the effect of giving you a closer ratio transmission.. So ALL of your gears will be shorter, and closer together..
I got 4.10's simply to eliminate the bog I had going from 1st to 2nd, along with more torque through the rpm range..
I do not think you would want or need 4.10's and 3.73's would be barely noticeable and probably not worth the money to do the swap.
I have always felt 3.90 is a great gear and is highly underused...
I wish I had them