All I have is a maintenance manual, and it doesn't have a thing to do with the heater. I have a '52 GMC, and I need to remove the heater and put a new 12 volt motor in it. While I'm at it, I will pretty it up as well, but I would like to see how the thing is supposed to come apart before I get started on this. The heater is the kind that pulls fresh air in from the side of the cab through a vent. Any help would be greatly appreciated!