You can tell by looking at the inspection cover. If the top and bottom is flat and the sides are round it is a 7.5". If it has four flat sides it is an 8.8". If you have a Summit or Jeg's catalog laying around, look in the axle section and it should have chart showing the gasket profiles. Ford didn't start putting the 8.8" in the 5.0L Mustangs until '86. If your car is an '83 GT it will have a 7.5" unless someone has already replaced it.
__________________ Thomas
1985 Mustang GT 5-Speed - See Profile for Mods |