im not sure where to search for help on this. i have a 1952 gmc truck totally stock but heater box say pontiac. im thinking my uncle, the original owner must have changed it . but truck is all like new so no idea why box says pontiace. core is shot. anyone know where to start looking for a core i found one but you need to use old tanks and im sure mine are no good as i had to put in a new rad well.any helpwould be appreciated