Can Someone Tell Me If These Gt40a Are Light?

90lxwhite

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#1
The a after gt40 was supposed to be an s. Ok so I was lookin at rebuilt gt40s from promar engines and they said they are from a cobra not explorer but have no thermactor ports so I email him asking if they are really cobra or from an explorer. Below is his reply, is he giving me correct info or is it bum dope?
You would have to measure for assembled height and spring pressure to know
if your beehive springs will swap over. The Cobras with the GT40 had there
Thermactor holes going right into the exhaust not into the head like the E7
heads. Ford did away with the Thermactor ports in the heads to create a
higher flowing port. Neither the GT40 nor the GT40P heads have this
provision. All GT40 and GT40P heads from the factory are pedestal mount. To
retain emissions legality you would have to run your Thermactor ports into
your manifold/headers. You should not run into any piston to valve relief
interference due to valve diameter but you should clay your pistons upon
assembly to check for valve interference due to lift, valve timing, and
duration.

Thank You
Promar Engine


-----Original Message-----
From:
Sent: Friday, August 23, 2013 3:29 PM
To: [email protected]
Subject: Reman gt40 heads


I saw the ad for he remanufactured gt40 on eBay and I have a couple
questions. I have beehive springs on my e7 heads on my 95 mustang gt can I
swap those over to the gt40? Also you state that the gt40s you are selling
are not from an explorer they are genuine cobra heads. But you say they
don't have thermactor ports, the cobras did. Those are early explorer heads
(not p) I have a cam w .512 lift and flat top pistons w valve reliefs think
I will have ptv issues? Are those stud or pedestal mount heads as far as
rockers goes? And w out the thermactor ports how do I retain smog legality?
Sent from my iPhone=
 
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Mustang5L5

Car used in adult film "Highway Gangbang-InDaButt"
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#2
Untrue.

93-95 Cobras and 93-95 Lightnings had GT-40 heads with thermactor ports. The ports were eliminated on the GT-40P's

Early explorer GT-40's may not have the ports. I wanna say they don't. Given that there are WAAAAAY more 1996 Explorer/mountaineers out there vs Cobras and lightning, i'd venture the vast majority of cores are these heads.

The ports are actually there, just undrilled on the 40P's
 

Rick 91GT

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Nov 29, 1999
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#3
Untrue.

93-95 Cobras and 93-95 Lightnings had GT-40 heads with thermactor ports. The ports were eliminated on the GT-40P's

Early explorer GT-40's may not have the ports. I wanna say they don't. Given that there are WAAAAAY more 1996 Explorer/mountaineers out there vs Cobras and lightning, i'd venture the vast majority of cores are these heads.

The ports are actually there, just undrilled on the 40P's
Correct

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90lxwhite

I'm kind of a She-Man
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#5
I emailed em back and said since you know and I know they are explorer heads you're selling for a cobra premium would you sell them for the cost of a rebuilt explorer head? We'll see what he says if anything.
 

94GTCoupe

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#6
Some early explorer/mountianeer gt40 heads do come with the thermactor ports, sealed with a threaded plug.

I've removed many of them.
 

90lxwhite

I'm kind of a She-Man
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#7
Either way I think I'm gonna stay away this guy wants 600 sum odd n not being honest as to what he's sellin
 

mikestang63

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Aug 27, 2012
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#8
The Cobras with the GT40 had there
Thermactor holes going right into the exhaust not into the head like the E7
heads. Ford did away with the Thermactor ports in the heads to create a
higher flowing port. Neither the GT40 nor the GT40P heads have this
provision.
The GT40 heads I pulled from a 96 had thermactor ports
Either way I think I'm gonna stay away this guy wants 600 sum odd n not being honest as to what he's sellin
600 for GT40 heads? Run I pulled mine from the JY for less than $100 and spent $125 for better springs and $200 to have them cleaned up and guides/seals done. I wouldn't pay more than 3-400 for a set.

For a few hundred more ($1000 range) you can get a set of aluminum heads that will perform much better, which is frankly what I should have done in the first place.
 

90lxwhite

I'm kind of a She-Man
5 Year Member
Aug 25, 2011
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372
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Between the Red and Rio
#9
The GT40 heads I pulled from a 96 had thermactor ports


600 for GT40 heads? Run I pulled mine from the JY for less than $100 and spent $125 for better springs and $200 to have them cleaned up and guides/seals done. I wouldn't pay more than 3-400 for a set.

For a few hundred more ($1000 range) you can get a set of aluminum heads that will perform much better, which is frankly what I should have done in the first place.
Yeah these are supposedly rebuilt and they state that these aren't from an explorer but "real cobra" but then it goes to say that they have no thermatcor. Promar is the company selling them