cool way to tell 3.73 from 4.10's. .

Most of you may already know, but for the noobs(more than me ) you can jack your car up and use stands so it doesnt fall on you and kill you, but put a dot on the bottom of the tire and one on the bottom of the driveshaft...spin the tire 1 complete turn.Count how many times the driveshaft turns and there you go...3 and 3/4 turns, you have 373's 4 turns and a little, you have 410's.
This is if you bought a car with gears already in it...