Engine 90 gt40p heads EGR/Thermactor question

pregnantgoldfish

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Mar 16, 2019
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Hi there citizens of stangnet. My car is not actually a mustang but a Lincoln mark 7 lsc. It has a very similar engine and i thought this would be a good place to ask about heads.
Now for my question. I have been looking at info on heads and have decided to get one of the two gt40 style heads. My problem is that im having a hard time finding non P heads and need to keep my EGR for fuel economy reasons.

Ive heard the P heads do not have the thermactor holes but would the EGR still work to any degree. I've heard the thermactor holes only are used when the motor is cold so would i still be able to use the rest of the EGR system to get good cruise MPG or will laking them completely break the EGR system.

If I sound like a complete noob its because most of my mechanic experience is with other cars. My mark 7 has been pretty good to me maintenance wise so i haven't had much hands on with the engine parts. Any help is appreciated.
 
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pregnantgoldfish

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Mar 16, 2019
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How much money you spending on these heads?
I haven't picked out any in specific yet. i just have noted on ebay the P heads are seemingly 300-400 and much more common while the the non p heads are either 500 dollars or more or only have local pickup in a different state.

Im trying to go for a more budget approach otherwise id pry be looking for some nice new aluminum heads.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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The p's are the better of the two but just slightly, they have plug clearance issues with some headers, for the money save up for some aluminum heads, I have p's but they were new when I got them so the money was right but that was years ago, now the advantages and affordability of aluminum heads make the money spent on gt40's wasted
JMO.
 

pregnantgoldfish

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Mar 16, 2019
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Do youk now if the aluminum heads have the EGR. I think I can get a set for around 600 but if they dont have the EGR or i cant retain enough of my EGR to keep mpg up ill pry have to pass for the time. I am aware the aluminum heads are better and tbh your probably right about spending a couple hundred more and getting aluminum if i have to go with P heads.
 

pregnantgoldfish

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Mar 16, 2019
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You can get the aluminum heads with and without egr provisions.
Alright awsome. So do you happen to know the answer to my question about the Thermactors by chance? I think i could get the gt40 intake upper and lower for cheap for the time being and then wait for either some aluminum heads or a great deal on the old style.
 

pregnantgoldfish

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Mar 16, 2019
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Thanks for the link. I actually came across this one earlier which is why im unsure. It sounds like I could keep my mpg and EGR section that runs when the car warms up so i dont lose any MPG but im just unsure if that portion of the system would still work if just plugged up the lines that would lead to the cold start portion of the EGR. I suppose it sounds like the warmed up motor portion of the EGR should still work.

I suppose im in a bit of a pickle because I think most people would just delete the EGR and move on with their lives lol.