No there are no external differences both the Preco (32000 series) and Equipco (33000 series) fans are not seen from the outside. That being said, some cars had a stencil or a flat metal plate where a fan pulley would be located above the truck. According to Ed Hawkins this might have been to alert employees that the cars had fans. On our website is a reprint of the excellent article on these cars by Ed Hawkins from the MPHS Eagle. With photos of the stencils and plates.
