You will need a 3.92:1 ratio 7" diff. The ratio is normally written on a tag that is located at the top left of the rear cover. The rear cover can easily be removed by taking the torx bolts out. The ratio of the diff (3.92) will also be written on the crown wheel.


When you remove the rear diff from the car, hammer the torx bit into the torx bolts to make sure it goes in deep enough. If you don't do that you will probably round off the bolt head and then it is time to take the angle grinder out.


To test that your new diff is actually an lsd, try to rotate the output flanges in opposite direction. On an open diff it will be very easy, on a lsd it should be difficult (if it is in good condition).