That's a picture of a First Gear 1/34 diecast on that box. It's not a C series truck. The C series they are talking about will be the same basic truck as the Stake Truck kit but with a van body. It's a reissue. It was issued as a Hertz Rental version, a Napa version and I think one more but I can't think of it right now.
Actually it is a C series truck, the first C series was offered by Ford 1953-56. The C series most know was introduced in 1957 and ran until 1990. Unfortunately I expect the box art was a goof. My first hope is Round 2 will respond to this mistake by tooling up the truck on the box to avoid admitting such a terrible faux pax. Failing that I hope they lock the artist in a small room full of televisions playing Barney the dinosaur episodes, as that is the only punishment remotely fitting the crime.