Well there's not going to be a lot, but 4:10's unless you have a hookup, will be easier to find than 3:92s.
You will notice the difference in et between either set and your 3:55's especially with a locking diff. The problem then will be traction, but with only 188 rw hp ( I figured that here)
http://www.ajdesigner.com/phphorsepo...horsepower.php traction shouldn't be an issue until you start making more torque.
Btw I took your weight and hp and calculated your et here...
http://robrobinette.com/et.htm