Thanks for the info on size of plug and temperature sensor, will try to run those down this week. As for the overheating issue I will try to work thru those. I know that my father-in-law had removed the thermostat and the heater core is missing and the lines running to and from are spliced together, so could have been leaking coolant there. He added a set of gauges below the dash that included oil and temperature, so not for sure what gauges if any actually work in the dash. The old head gaskets looked good but I am replacing. But up till six or so years ago he drove it everyday.

If you put the sender in the manifold, then you also have to choose not to have heat.  Not a problem if you don't drive year round.  Big problem if you do.

One thing to realize is that with the sender in the stock location and assuming that the gauge is accurate, then the engine temperature is actually about 15 degrees higher than indicated.


Lawrenceville, GA

Now why didn't I think of that?

Wait a minute. How about putting it on the RS head? But then again, that old style HTR CTL VLV has to go.

Learn something new everytime I open this page up.

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The size for the expansion plug for the right side head located at the rear of the intake manifold and under the distributor cap is 59/64”.  The factory location for the coolant temperature sending unit was on the opposite side head in the corresponding hole.  Starting in 1957, the bung for that hole had a ¼” NPT thread.  Before 1957, that threaded hole was a 3/8" NPT.  It’s totally acceptable to move the water sending unit to the front of the manifold which typically gives a slightly warmer reading on the gauge.
 
The number one cause for cracked heads is overheating.  Low coolant levels are a major contributor to this but thermostats, reduced coolant flow, blocked passages, leaking head gaskets, ignition timing, and water leaks in general are all factors to be considered.  If the engine has set for a long period of time, then coagulated and/or hardened coolant within the block and cylinder heads becomes a real problem.

Lorena, Texas (South of Waco)

Not for sure what caused the heads to crack. I know that a guy in town here told me that he had repaired one of the heads. Not for sure how that is done and if that led to other problems. Thanks for the resources and will check or post in the classifieds when looking for parts from now on.

Great source of info and casting numbers

http://www.ford-y-block.com Bottom of the page

Great source of test, articles, etc.

http://www.eatonbalancing.com

Got any idea why the heads cracked?

You can often do better here in the classifieds than on eBay. You might also pick up a copy of “Ford Y-Block Engines” by C Morris. Amazon has them. Y blocks have some quirks, “don’t put the long bolt in this hole” or how you install the timing chain. Ted Eaton’s articles cover a lot of that.





miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

My father-in-law drove the truck daily till about 6 yrs ago and owned probably 15 years and the way I remember is it always had a overheating problem. When he passed about 5 yrs ago it just sit. Both heads turned out cracked, so I found some on Ebay and then had them resurfaced. The ones I bought on Ebay had no core plugs in them, but the guy who did the work told they would need them and a heat sensor. I am concerned about all the coolant and oil that I drained out, not for sure what I need to do. I am in Ranger, Texas which is the middle of nowhere. What's you opinion about buying parts on Ebay, is there better sources. Thanks again

Give us a little more background. How long since the truck has run, or is it running. Your general location. Why the head change, etc. there’s lots of really good help here and knowing a little more will let more points be made on what to look for.

Welcome to the site.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Great, thanks. I inherited this truck with the passing of my father-in-law and I know this is probably an elementary question but for I guy who has never done more than oil changes I need all the help I can get. This is the first of several problems I have to work through, but I am determined to get it running again. Thanks again

1 core plug at the rear of the intake flange for the passenger's side head.  The temperature sender goes in the same location on the driver's side head.


Lawrenceville, GA