Gt40 heads

RonBurgandy · Dec 16, 2013

I'm gunna go grab some pull yard gt40 heads sometime this week. I was gunna have some home porting done (by a credible friend) not going to worry about bigger valves or anything like I did with my last set. Just curious if the stock valve springs are fine to use with a stock 5.0 cam.

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CC'S95GT · Dec 16, 2013

I'd say probably not.
the exploders dont turn the rpm's that the mustangs can. springs are fairly cheap anyway.

RichV · Dec 16, 2013

Any GT40/p from a explorer, no. If you get them off a Cobra then yes.

The explorer cam is not worth anything over 5K rpm, either are the springs.

CC'S95GT · Dec 16, 2013

RichV said:
Any GT40/p from a explorer, no. If you get them off a Cobra then yes.

The explorer cam is not worth anything over 5K rpm, either are the springs.

I was thinking that when I was replying but a I assumed he was getting exploder heads.

RonBurgandy · Dec 16, 2013

Yep explorer heads are a dimr a dozen around here. They can be had for $60 for the pair. And I figured id have to change them a bit.

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full force · Dec 16, 2013

Springs are most likely the same even though you would not think so...remember the 96-97 Explorers use the standard Motorsport gt-40 heads, not P heads

Win · Dec 16, 2013

I thought it was midway through 97 some of them had p heads depending which plant they came out of.

RichV · Dec 16, 2013

full force said:
Springs are most likely the same even though you would not think so...remember the 96-97 Explorers use the standard Motorsport gt-40 heads, not P heads

They are absolutely not the same. Change them.

full force · Dec 17, 2013

Win said:
I thought it was midway through 97 some of them had p heads depending which plant they came out of.

late 97 did yes

full force · Dec 17, 2013

Why wouldnt they be the same? think about it, they made the heads for the 93 Cobra, they will not just chage to a WEAKER spring just because, same as updating casting to the P series, just becasue the explorer does not rev as high, even though a stock 5.0 does bot either, ever put a stock engine on a dyno??? peaks around 4800-5000....now I have to research to see whos right, show me facts then I will believe ya...

RichV said:
They are absolutely not the same. Change them.

95RedGt · Dec 17, 2013

I tried running the stock gt40 3bar heads Of an explorer. I did get valve float. I since changed to tfs1 cam and spring kit.

full force · Dec 17, 2013

Did you just put heads on? Most stock springs are smoked anyway I would always put new springs on them chances are you bolted them right on not new springs

RichV · Dec 17, 2013

full force said:
Why wouldnt they be the same? think about it, they made the heads for the 93 Cobra, they will not just chage to a WEAKER spring just because, same as updating casting to the P series, just becasue the explorer does not rev as high, even though a stock 5.0 does bot either, ever put a stock engine on a dyno??? peaks around 4800-5000....now I have to research to see whos right, show me facts then I will believe ya...

If you know your GT4 heads (3-bar) there are like 3 different variations, why is that?

95RedGt, a real experience. Same with many local friends, been doing GT40 heads probably before most of you guys were driving. I don't need to prove anything to you, don't believe me then. But this is how bad info gets circulated around the net. Real experience versus guesses.

I have personally never seen stock valve springs get tired. Specially on a Explorer that rarely lives past 3000rpm. If I was going GT40 3 or 4 bar out of an explorer, I would at minimum use the springs from the E7s.

full force · Dec 17, 2013

I'm new at this.... I'm 19 years old .... Not!! I am basically saying if you want any performance at all a smart person would spend the chump change springs cost and make sure there is no issues!!!! I been doing this over 25 years myself I know what I'm doing.... Nobody builds engines and just tosses whatever on them if they actually give a chit how it will run!!

RichV said:
If you know your GT4 heads (3-bar) there are like 3 different variations, why is that?

95RedGt, a real experience. Same with many local friends, been doing GT40 heads probably before most of you guys were driving. I don't need to prove anything to you, don't believe me then. But this is how bad info gets circulated around the net. Real experience versus guesses.

I have personally never seen stock valve springs get tired. Specially on a Explorer that rarely lives past 3000rpm. If I was going GT40 3 or 4 bar out of an explorer, I would at minimum use the springs from the E7s.