Rear-end's Gearing: How do you know

How do you know what size rear-end you have (where do you measure..ex: 9" read end)..also ..how do you know what gears are in it?

If you have a 9" Ford, a socket will not fit on the lower nuts connecting the carrier to the housing.
If there's a tag attached to one of the nuts post the info here, and someone should be able to tell you the ratio.

u can calculate the gearing:

AXLE RATIO= RPM x TIRE DIAMETER
-------------------
MPH x 336

To find the gear ratio. This is easier done with two people, mark the drive shaft with a daub of paint or caulk, mark the sidewall on one of the rear tires with caulk where it meets the floor, have someone push the car until the tire makes one revolution count how many times the drive shaft turns. It's close enough to get in the ball park. Three and a bit turns 3.10:1 three and a half turns 3.50:1 five a half turns hope you own a gas station.
Gerry
[addsig]