How much gain with lower gears?

You will see several tenths shaved(as much as 4 tenths possible) if you choose the 3.73's over the 3.23. A 408 will like them.They are quite street friendly and not too bad on the open road with speeds under 65.Several of my PA friends run them in their street cars.They are from south western part of the state with lots of hills and twist and turn roads.Not many places to top out the speedo so tighter gears work well in that area.Gettysburg is a bit hilly if I remember.Not as flat as the south eastern part of the state. Out here I have open long stretches of flat land. 2.76 feel like 4.10's with no overdrive.