When I bought the '47 panel I was handed a heater for it. (It had "50 Chev" in paint marker written on it.) When I compared the heater to the truck I found that it was not configured the same as the holes in my firewall.

The alleged "50 Chev" heater has the hose fittings in a horizontal line with the electric motor. The fittings are about a foot or so apart with the motor in the center. The holes in my firewall have the hoses coming in below the heater motor, about 4 inches apart.

I got in touch with a guy in the swap meet with an AD heater and he sent me a picture of the same thing I already have. I really do not want to make more holes in the firewall because this is a temporary solution until I get to a more modern system anyway.

Was there a change in the heaters or am I looking at it wrong?

What is the purpose of the large hole in the firewall? It does not appear that the heater motor protrudes through it. Is there supposed to be an inspection/service cover there?

Don't lose your head to save a minute,
You need your head, your brains are in it.
Burma-Shave (1947)