not necessarily changed Boyd, the 57's can be found with electric [especially cars], but they were an option [RPO 320 for trucks], the vacuum was standard .... could also have been installed by a dealer on request
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
