The Stovebolt Site Forums The Parking Lot Tons 'o Fun anyone change out their 5.17:1 diff gears?

Do the math 5.14 divided by 4.11=1.25or 25% increase in speed per rev of engine 5.14 divided by 4.56 = 1.127 or 12.7% increase per rev of engine.
If this math is flawed, let me know the error of my logic.
Jerry