Ok I bought 1961 Suburban, mounted on the pasengers side of the firewall there is this black box. I haven't gotten the truck home yet so investigation is only through pictures at this time. I'm thinking that it's heater core maybe. But it is nothing that I have seen before after many months of looking that these trucks on the web I've not seen this before. It almost looks like and Air Conditioning unit. Please some one confirm the Subject title. "I'm an IDIOT" I can't seem to get a picture to post in here but will be happy to send it to anyone willing to confirm the above....
Thanks,
Mark