What is the stock gear ratio of a 1990 Mustang GT?
I called to have my gears swapped at a place because I want to put my 4.10s in (its an AOD) and he asked me for the gcode and my current gear ratio.
Look at the tag on your rear end cover. It will say something like 2L73, or 3L08. They did also put 3.27 in the rear too. My friends 89 gt with an auto had them.
Nether one of those numbers are the gear ratio. It should be the top number near the bolt. The bolt might cover a little of the first number, but there is a code that reads 2L73, or 3L08, keep looking. Or just jack up the rear and count the tire rotation to the drive shaft rotation, ie 1 turn of the tire for every 2.73 turns of the drive shaft.