Since my crystal ball is in the shop, I have no way of knowing the model year of your car, if it still has the stock automatic transmission or much of anything else about your car.
That's why it is a good idea to use the sig under the user control panel (User CP) option. It allows you to post your car year & mods, which help greatly when troubleshooting things. No, it is not there for us to snoop and see any "Secrets" you have hidden away under the hood. Be a good stangnetter and update you sig for future reference & don't keep us guessing.
According to the spec sheet, it will not fit the stock auto AOD trans that comes with most 1980-93 auto transmission Mustangs. Nor will it fit the 94 and later AODE auto transmissions.