Since it's too cold to get motivated to do much welding, I've decided to try and clean up my heater box and get it ready to go since I can do that in my basement. The one from my car has some issues I don't want to tackle, so I grabbed two more from the pile of parts at my buddy's house. Each of those have minor problems as well.
As I was disassembling them and making sure they were identical to what I need, I noticed 2 have "Ford" embossed on the outside and one has "Fomoco"(I might have that reversed). I seem to remember reading that Ford changed the designation they used at some point... but I don't remember when? Can anyone tell me what year this change was made? The cases are very nearly identical as far as I can tell, but combining the halves of each does not work perfectly as there are alignment issues.
One had a heater core with a C9 part code and the other had a D1. This makes me wonder, did 71-73 use the same heater box?
One more, would a car that came with AC have a different box?
Thanks!