[George Conboy]

In the middle of an engine rebuild for my 1965 Valiant 200 Wagon. There's a plug in my cylinder head and the plug is cracked. Tried the suppliers I've used in the past (Bernbaum, Roberts Motor Parts, Kanter) but no luck. Any idea where I might find one?

 

[Scrounge]

If you mean the freeze plug, found this:

- Freeze / core plug kit slant 6 170,198,225 brass #fpk-112b (at https://headbolts.com/store/p/228-Freeze-/-core-plug-kit-slant-6-170-198-225-brass.html )

 

[George Conboy]

If you mean the freeze plug, found this:

- Freeze / core plug kit slant 6 170,198,225 brass #fpk-112b (at https://headbolts.com/store/p/228-Freeze-/-core-plug-kit-slant-6-170-198-225-brass.html )

I don't think that's it (there's no photo, and says "does not include any head plugs"), BUT that's a great parts source and I have emailed them to ask if they have what I need. Thanks for the lead!

 

[Adventurer55]

I had a 63 Valiant wagon. My first car in 1976. 170 3 on the tree originally. 170 became tired and we installed a freshly rebuilt 225. Much much better. Sold it in 77 and bought a 72 Duster.

 

[ImperialCrown]

The 1965 Mopar parts catalog shows no freeze plugs (also called core plugs or soft plugs) on the slant-6 head, only on the block. There is a threaded plug in the head for vehicles that didn't have the optional heater.
There was a head redesign in 1974 where it got one freeze plug.
I don't think that this is a freeze plug. Can you find and post a picture of it from the internet?

 

[GLHS60]

I'm guessing a spark plug tube??

Thanks
Randy

 

[Bob Lincoln]

Can the OP post a photo?

 

[Scrounge]

If it's a threaded plug as IC describes, and you can remove it, you might want to measure the thread size (if you don't have the device for that, a parts store might), then see if you have any strong bolts in your bolt jar or on your work bench that are an exact fit. Or buy one from a hardware store. That might work until you find a supplier that has the correct OEM or after-market plug.

 

[ImperialCrown]

I think that pipe threads are the standard used.
National pipe thread - Wikipedia (at https://en.wikipedia.org/wiki/National_pipe_thread )