The Centurion began life as a four-door club cab short bed F-Series pickup. To it was added a Bronco tailgate and fiberglass cap to close off the bed. A third-row bench was also donated by the Bronco to make the Centurion capable of carrying 8-9 people.
This particular Centurion is built off of the eighth-gen F-Series, though Centurions were also built on the ninth-gen F-Series up until 1996 when the tenth-gens arrived. It's powered by Ford's big 7.5L 460 c.i. V8 using the three-speed C6 automatic. Sure, it's got 220,000 miles on the odo and needs some TLC, but chances are any interested parties aren't looking for a show vehicle.
[Source: eBay Motors via GM Inside News]