Howe Radiator Overflow?

[ntsqd]

Put a t-stat in it with the plug out and sight down thru the hole where the plug is. My guess is that they will interfere with each other.
OTOH you might be able to drill and tap a housing to place the anode coaxial to the t-stat. On the end below the hose bib of a housing like this:

 

[ba123]

That housing is the one I already have in so will see when I try.

Otherwise will have to revisit the drop in idea or something like this:

 

[bigmuddy]

There used to be an anode option where the anode hung from a ring that went under the radiator cap. Haven't seen one advertised in a while.

I have one like that. See if I can find a picture

 

[ntsqd]

That would be good. One of the questions that the mental image that I have can't answer is how it sealed on the bottom.