There are 2 versions of the Hiway Hauler. The first Hiway Hauler was made from the cab used in 1973 for the Road King Truck whaich was part of a set. I then proposed using the cab again for the American Hauler and American Tipper in 1976. The cargo boz on trhe Hauler was very similar to the final versionb we made for the Hiway Hauler in 1980 with the extended box and extra set of wheels. The sid eof the box was perfict for many other tampo designs we used like Pennzoiil, Mountain Dew and so on.