408 EFI going back together and have questions

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I'm trying to get anything else I might need while putting everything back together. As mentioned I'm using a full Holley Sniper kit with their ignition kit. I'm going to be using after market gauges for temp, volts and oil.  I'm running electric fans so where is the best spot to put that sensor. I seemed to have miss placed my T-stat housing lid. I know some people use that as a port for the sensor. What housing lid do you guys suggest? I currently have a 195 stat with the matching fan sensor. Should I be using a 185 for both? Car will be a fun driver for spring, summer and fall so I don't plan to drive much in the winter. I remember reading that the Cleveland likes to run hot but wasn't sure about a 408 configuration? Also I'll be using a CVF serpentine kit with AC delete so all of that will be new along with a new kool flow water pump. So anything else I'm missing? Aything else anyone want to add while everything is out of the car? Thanks

 
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I don't believe that any 351C thermostat housing has a threaded port that a sensor could be connected to. You can get a t-stat housing for a 460 or 400M that has the threaded ports that will work. However, they are angled about 45° forward and not straight up like the Cleveland housing and will require modification of the upper radiator hose, or maybe using the upper hose from a 460 or 400M. This housing is for a 400M

https://www.rockauto.com/en/moreinfo.php?pk=819083&cc=1123197&jsn=558

The housing for 429s in Mustangs appears to have a 90° outlet and do have a threaded port.

https://www.npdlink.com/product/thermostat-housing-water-outlet-c8sz-8592-a/106435/200384

And the upper hose for it may be the easiest to fit

https://www.npdlink.com/product/radiator-hoses-concours-pair-d1oe-8b274-ba-d1ae-8b273-ba/106617/200382

Because you will not be using it for a daily driver or touring, a 185° thermostat should be fine. The primary reason for a higher degree thermostat is for fuel burning efficiency. You could use the lower temperature sensor with the higher temperature t-stat, also. That way if you don't like the way it runs with the 195° t-stat all you would have to change is the t-stat.

And, you could use the threaded/plugged port in the side of the water pump. But because this is coolant after it circulates through the radiator I would use the 185° sensor at that location.

 
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I have 3 temp sensors on my 351 with sniper.

One two near pump (as Don C explained), and I also have one at the bottom of the radiator. I use that one for my electric fan.

But if you use the Sniper to trigger, you do not need this one at all. You need the unit connector to match your relay connector.

Something I still need to do.

 
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I myself prefer the 195 thermostat. That gives the coolant more time in the radiator to actually cool. Also if you have an automatic transmission I would go to a stand alone cooler to take that heat out of the radiator also. I do not have a 408 but I do have a 351 bored .050" over and flat top pistons, cam with AC. Has holley 4-V and MSD ignition. I can drive in any heat in the 90's and stop and go and no heating issues. I did put a Hayden trans. cooler on my automatic. I fabricated brackets that used existing threaded nuts in the radiator support so looks sort of factory.

 
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I myself prefer the 195 thermostat. That gives the coolant more time in the radiator to actually cool. Also if you have an automatic transmission I would go to a stand alone cooler to take that heat out of the radiator also. I do not have a 408 but I do have a 351 bored .050" over and flat top pistons, cam with AC. Has holley 4-V and MSD ignition. I can drive in any heat in the 90's and stop and go and no heating issues. I did put a Hayden trans. cooler on my automatic. I fabricated brackets that used existing threaded nuts in the radiator support so looks sort of factory.
Good to know. I'm running a TKO 600 so no worries about the auto.

 
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I'm trying to get anything else I might need while putting everything back together. As mentioned I'm using a full Holley Sniper kit with their ignition kit. I'm going to be using after market gauges for temp, volts and oil.  I'm running electric fans so where is the best spot to put that sensor. I seemed to have miss placed my T-stat housing lid. I know some people use that as a port for the sensor. What housing lid do you guys suggest? I currently have a 195 stat with the matching fan sensor. Should I be using a 185 for both? Car will be a fun driver for spring, summer and fall so I don't plan to drive much in the winter. I remember reading that the Cleveland likes to run hot but wasn't sure about a 408 configuration? Also I'll be using a CVF serpentine kit with AC delete so all of that will be new along with a new kool flow water pump. So anything else I'm missing? Aything else anyone want to add while everything is out of the car? Thanks

...welded bungs into standard thermostat housing for fan controller and high temp warning light. 192° "top hat" style thermostat. 408 stroker, similar build to yours. No overheating, ever.



 
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Nice.

Did you have to extend the neck? I have a couple of them, and I don't think there would be enough left after welding the bungs on.

Hey Don, Merry Christmas!  No extension on the neck, just a nice tig weld and a normal worm drive clamp. It's been on there since 2015 with no issues.





 
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Yes, it is that time of the year, can't believe it's here already.

Merry Christmas.

I see you're not using the normal temperature sender location right below the t-stat housing.

Well done on the housing neck, good looking welds.

 
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Yes, it is that time of the year, can't believe it's here already.

Merry Christmas.

I see you're not using the normal temperature sender location right below the t-stat housing.

Well done on the housing neck, good looking welds.

At the time of that picture the sending unit for the temperature gauge hadn't been installed yet. The other 2 senders installed in the thermostat housing are for the electric fan controller and high temp warning light (completes ground @ 220°), located in the center dash panel just above the temperature gauge, just in case I'm not paying attention.

 







 
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Yes, it is that time of the year, can't believe it's here already.

Merry Christmas.

I see you're not using the normal temperature sender location right below the t-stat housing.

Well done on the housing neck, good looking welds.

At the time of that picture the sending unit for the temperature gauge hadn't been installed yet. The other 2 senders installed in the thermostat housing are for the electric fan controller and high temp warning light (completes ground @ 220°), located in the center dash panel just above the temperature gauge, just in case I'm not paying attention.

 







Hey Eric, got my account back up. Looks good. You mentioned your T-stat is 192 but what temp is your sensor for the fans?

I have to find out what temp my EFI will go into closed loop at. If I have a 195 T-stat would I want to use that matching temp for the fans? Just want to make sure I'm not cooling too much and cause open/closed loop issues.

 
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Yes, it is that time of the year, can't believe it's here already.

Merry Christmas.

I see you're not using the normal temperature sender location right below the t-stat housing.

Well done on the housing neck, good looking welds.

At the time of that picture the sending unit for the temperature gauge hadn't been installed yet. The other 2 senders installed in the thermostat housing are for the electric fan controller and high temp warning light (completes ground @ 220°), located in the center dash panel just above the temperature gauge, just in case I'm not paying attention.

 








My controller, located under the dash, has the ability to customize the setting of the range where they first turn on and increase their flow up to 100%. I have it set to turn on at 197°

 
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At the time of that picture the sending unit for the temperature gauge hadn't been installed yet. The other 2 senders installed in the thermostat housing are for the electric fan controller and high temp warning light (completes ground @ 220°), located in the center dash panel just above the temperature gauge, just in case I'm not paying attention.

 







Ok. How about the shut off temp?

 
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So from some of the stuff I'm reading sounds like my best bet would be to get a 180 T-stat and run a 195 fan switch. Obviously it makes sense that the fans turn on after the stat opened otherwise the fans would be on before the engine even gets up to temp. Either that or I look into utilizing the sniper controlling feature.

 
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Hey Eric, got my account back up. Looks good. You mentioned your T-stat is 192 but what temp is your sensor for the fans?

I have to find out what temp my EFI will go into closed loop at. If I have a 195 T-stat would I want to use that matching temp for the fans? Just want to make sure I'm not cooling too much and cause open/closed loop issues.

My controller, located under the dash, has the ability to customize the setting of the range where they first turn on and increase their flow up to 100%. I have it set to turn on at 197°
Ok. How about the shut off temp?

If I recall correctly the range is 15°±.

197° on 182° off...195° on 180° off, etc.

So where I have mine set keeps me at the optimal temp of 193°ish, which is where the Cleveland wants to be. (as designed by Ford)

 
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Yes, it is that time of the year, can't believe it's here already.

Merry Christmas.

I see you're not using the normal temperature sender location right below the t-stat housing.

Well done on the housing neck, good looking welds.

At the time of that picture the sending unit for the temperature gauge hadn't been installed yet. The other 2 senders installed in the thermostat housing are for the electric fan controller and high temp warning light (completes ground @ 220°), located in the center dash panel just above the temperature gauge, just in case I'm not paying attention.

 







To your point, I have my fans set to turn on @ 197° so that they will only turn on if the radiator cannot keep up when the thermostat opens at 192°. I notice Spring, Fall and of course winter when I go for a cruise, my fans never need to turn on.

 
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I like your warning lights. Idiot lights are better to have than just a gauge. When I went to the NASCAR driving school with Seat Time Racing they wanted us to check oil gauge each lap. LOL they had a huge red light in center right in front of you if you lost oil pressure it came on. You did not have time to look at the gauge. Same when driving in traffic or curves like we have here. The gauges being in the center does not help either. Would be interested in how you hooked them up. I am not any good with car electric things, lol.

 

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