Yup, the late 70's Lincoln Versailles had 9" axles with rear disks. However, in MY opinion it would be a monumental mistake to try & find then swap these onto a Bronco. Before you even consider it take a moment or two and make a few calls to price out replacement calipers for this car. They're *unbelievably* expensive. If you're really ******** about wanting rear disks then you're much better off just buying a kit from someone like Stainless Steel Brakes and being done with it. Trying to use one-off 30yr old factory parts is just asking for trouble.
Rear disks really won't do much to improve your breaking though. Roughly 75% of the trucks braking capacity comes from the fronts and since they're already disks the improvement of going to rears disks is minimal. It'll look cool and you'll certainly have bragging rights but that's going to be about it.
