[blykins]

You can snag a ring and pinion for around $185 down here in the States from Jegs or Summit Racing. If you've had the rearend cover off, sometimes the ratio is stamped on the end of the pinion gear. Otherwise you know you can check it by putting a mark on the driveshaft, and a mark on the axle hub....spin the driveshaft...count how many times you have to turn it to turn the mark on the hub around once. I'm sure you knew that, but it's a quick way to tell. I'm thinking since the Stang had a 6-banger in it, the gears may be low....you may already have a 3.55 or 3.73.

Take care and good luck.

Brent