This doesn't look good!

[m78]

Broke down and tried NAPA. They don't have any in stock at the regional warehouse.

Does this mean you were not able to try the NAPA ?

 

[fatherdoug]

Does this mean you were not able to try the NAPA ?

Correct. None in stock. It appears to be the correct configuration. It lists the thermostat(TH297) as a bottom-bypass style.

 

[Big Jim F150]

That's strange that you guys have trouble finding thermostats for the M Series engines 351M / 400. Try the local Ford dealer, they could get you one, for last year while my78 F-150 Ranger Lariat was at the Ford Dealer for distributor issues, while it was there I had them put a new thermostat in for me, and they didn't have a problem getting one. So Doug try your local Ford dealer and see if they can get you one, for you have the same engine in your truck, that I have in my truck, the M Series 351M / 400. hopefully you find this helpful.

 

[fatherdoug]

That's strange that you guys have trouble finding thermostats for the M Series engines 351M / 400. Try the local Ford dealer, they could get you one, for last year while my78 F-150 Ranger Lariat was at the Ford Dealer for distributor issues, while it was there I had them put a new thermostat in for me, and they didn't have a problem getting one. So Doug try your local Ford dealer and see if they can get you one, for you have the same engine in your truck, that I have in my truck, the M Series 351M / 400. hopefully you find this helpful.

They don't have one and can't get one.

 

[m78]

Whats a good price Doug ?
Just saw this one is a 195*

http://www.ebay.com/itm/271664504517

 

[smokey]

Rockauto has several listings

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1120925&parttype=2200

 

[fatherdoug]

Whats a good price Doug ?
Just saw this one is a 195*

http://www.ebay.com/itm/271664504517

That one disappeared. Somebody must have bought it. Thank you, Mark.

Rockauto has several listings

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1120925&parttype=2200

Thank you, Randy. I think some of those will work, but I'm not sure of the quality. The one Motorcraft that is listed is an RT-1139, which is for a Windsor engine. I need an RT-139.

 

[m78]

That one disappeared. Somebody must have bought it. Thank you, Mark.


I need an RT-139.

I might be missing something, but it says there's 9 left.

 

[TMI]

FYI...351C and 351M/400 do not use the same thermostat.
351M/400 do not require the "top hat" on the thermostat.


351C block

351M/400 block

 

[fatherdoug]

Thank you, Tim. Now I'm confused, if I remember right, the thermostat well on my 400 looks like the top picture?

 

[fatherdoug]

I might be missing something, but it says there's 9 left.

You're right, Mark. Looks like somebody bought ONE of them.

 

[DNFXDLI]

FYI...351C and 351M/400 do not use the same thermostat.
351M/400 do not require the "top hat" on the thermostat.


351C block

351M/400 block

I'm confused as well now....I just went and looked at my block and it is the way the 351C shows

 

[TMI]

See...we are human. I went and looked and found a few other 400 blocks that look like the 351C water outlet.

This thermostat we purchased from a local Carquest. We used it in a 351C engine.
Part #30089, just a few bucks.

 

[fatherdoug]

Thank you very much, Tim.

 

[DNFXDLI]

Thanks Tim!

 

[fatherdoug]

Whats a good price Doug ?
Just saw this one is a 195*

http://www.ebay.com/itm/271664504517

This was delivered today. It is a NAPA THM 297 thermostat. It was $9.95 with free shipping. The NAPA website lists it as $6.99. At least he didn't try to make money on it.

 

[TMI]

OK...I have totally screwed up now!!!

The pictures that I have posted about the water outlet, I have them labeled backwards.

The large hole, is the 351C outlet, but without the brass restrictor.
Hence the larger hole.

SO...the 351C (top-hat) style of thermostat should not be needed in the 351M/400 block.

I am very sorry for any confusion I may have caused, when you look at Ford and Cleveland style blocks all day, I can confuse myself.

 

[fatherdoug]

With the amount of work that you have done to remove the 400 from boat-anchor status, you're forgiven. Thank you.

 

[TMI]

Thank you!!

It does make me feel kind of dumb.

But as far as "boat anchors"

I am feeling that with the latest builds, we have a 434 that has now made over 620 HP on the street, if it fits, it can be the better choice.

Now the advantage that the 400 has, is in the last few years of being in a truck, I feel the casting are thicker and stronger.
If a 351C block was making 600 HP on the street, it probably would not last very long before it split the cylinders.

 

[fatherdoug]

Boiled Thermostat for lunch. This NAPA 195* thermostat started opening at 185* and was fully open at 195*.

Might try this one until another one arrives.