Hello. I am thinking of buying a 2014 Mustang GT from a private seller who basically bought the car to flip. Low miles at 64k and the price is thousands below book. This would be my first Mustang so I don't have much knowledge. He claims previous owner put a "racing" rear end in it. I have a picture and was hoping someone could help identify it for me. He also told me he missed third and hit first driving it at 35 mph and the car bolted but it didn't do any damage. Any help would be greatly...

Help identifying rear end