1954 dodge c-1 heater

[polaris400cc]

Trying to decipher the holes in the firewall to figure out what heater or heaters this truck may have had in it.
The one picture with the black dots is where I "think" the holes for corresponding model #'s would have the inlet and outlets for the heater core.
Does anyone have any thoughts on the correctness of my diagram?
By my diagram I think it has a model 36 in it, am I correct?

The other holes in the firewall also seem to correspond with a model 61 or similar mounting pattern, but from the other truck I compared it to seems a little off location.

[polaris400cc]

And do these holes look like they might line up appropriately for a model 61 or similar heater... just throwing out ideas here

[53Crusher]

Model 65

My 53 has a Model 65 heater with the associated holes. They seem to be in the same location you show for a 61.... Hopefully you can see the copper tubes sticking out by my remote oil filter.

[53Crusher]

Better Model 65 :-)

I thought these pictures would do a better job of illustrating where my mounting holes are for my 53 with a model 65. Studs are 3.5" Wide center to center and 8" Long center to center. Copper Heater core tubes are 10" Center to Center. These pictures might do a better job of illustrating that the mounting studs are not in a nice rectangle. Notice how one side is staggered from the other. Once again, hope this is helpful.

[polaris400cc]

Thanks, I will compare some measurements with my firewall. Im not sure, but seems like this truck may have had one or more different heaters in its lifetime. Not that that is hard to believe.

What does a model 65 have for knobs or levers on it or on the dash?

Not sure what goes in the far right two holes. The one toggle switch is just there for a temporary fuel pump, so I could move the truck around under its own power.

Sorry for my lack of any real knowledge on these trucks. Im more knowledgeable on 60s 70s mopar cars. And this is the first truck we have purchased. So im learning as we go here.