Power comes from a Corvair drivertrain and the structure is made from aluminum ribs with an aluminum outer skin, creating a rigid tube. The interior looks an awful lot like something you'd see in a Chris Craft of the same era. Without a frame underneath to get in the way, there's a ton of space in these things! The similarity to aircraft construction is no accident. UltraVan designer David Peterson was an aircraft designer frustrated that he had both a camping trailer and boat that he wanted to use during the same trip. In essence, the UltraVan grew out of the idea of just putting a drivetrain into a trailer. The Corvair had just debuted at the time, offering the perfect power unit for this application. The vehicles ended up being light enough to use regular car tires and return respectable fuel economy despite their large size (efficiency always makes you feel smarter than the next guy). We can't get over how roomy the UltraVan is, nor how lovingly the legacy has been cared for by legions of admirers.
Of course, we want one.
[Source: The UltraVan page via Hemmings Auto Blogs]