3.23 to 3.55?

I have 3.73 in my duster with a 275/60/15 , we run 2600 rpm at 60 mph. I went from a 3.08 to a 3.55 in my vette with a 255/60/15 gained 500 rpm, no big deal. The trade off was the car just plain drives better with more gear, accelerates nice and is not doggy at all.