What gears do I have?

Figure out what your transmission gear ratio is....then search the internet for a calculator. You can figure it out from there. I like to use Wallace Racing, he has great calculators.

http://www.wallaceracing.com/Calculators.htm

Joe

Or...put the car on jackstands, get under it, mark the inside of a tire and mark the driveshaft. Turn the tire until it makes one full rotation and count how many rotations the driveshaft makes.

If you want to do it by calculations, it's easier to use 4th gear because it is a 1:1 ratio. Also, you are at the mercy of how accurate your speedometer is if you are calculating the ratio based on speed.