Here's the beginnings of what goes into a Currie crate axle. The centersection is available in either '57-'66 style with the rounded pot or '67-up with the bulge. As a rule, most look like this one. If you want the correct nine-inch housing for a '65 Mustang, you will need the rounded housing common prior to '67. If you're installing the rear in a '67 like us, you need this one. Currie centersections are manufactured by U.S. suppliers, so you're getting American quality and keeping Americans working.