Packard Forum Index » Post-War (1946-54)

I am rebuilding a 54 359 with the aluminum head. There was no temperature sender in the head, only a plug where the sender should go. Upon removing the plug, I found that its diameter is 3/8 NPT, not the 1/4 NPT that every other post war Packard uses. I even have a spare aluminum head and it takes a 1/4 NPT!
There is no listing at Max Merritt or Kanter for a larger diameter temperature sender. They both show the same sender for all 51-54.
Is my situation unique? Does anyone else have the larger size hole? If you do, what temperature sending unit are you using?
I believe that there is an adapter available to reduce the hole size but I thought I would see if there is a different option.

All the ones I have seen have the normal 1/4 npt. What you have is somone's repair or the leftovers of an aftermarket temp gauge installation. You can get a nice brass reducer at any hardware store.

Echoing Ross's comment above, I replaced the sender a few years back with one from Merritt. Had no complications develop in the remove/replace operation.