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  •  » Junk Yard Gems

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    4/22/2014 4:22 PM  #1

    ultrastang
    I FYI 24-7

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    From: Camden, Arkansas
    Registered: 4/01/2013
    Posts: 570

    Junk Yard Gems

    I found a couple of Explorer 5.0L engines out in the local wrecking yard. One was a pre-'97-1/2 with the 3 Bar GT40 (Cobra) heads and the other Explorer 5.0L was a '97-1/2-up with the 4 Bar GT40P heads. Supposedly, someone had bought the engine with the 3 Bar (Cobra) heads so I grabbed the GT40Ps. 

    I know they aren't as good as a set of aluminum heads but they are superior to the old factory 289 HiPo heads. Besides the revised spark plug location, they also have a 58cc combustion chamber compared to the 3 Bar Cobra head's 64cc's. They're supposed to be good for a 20-40 hp gain.



    Notice the (4) bars cast into the end of the heads --thus, "4 Bar Heads." GT40/Cobra heads will have 3 bars in the same location.





    ....also got the harmonic balancer with 36-1 trigger wheel for an EDIS ignition system and I grabbed the oil-to-water cooler. All this was less than a $100.00 bill so, I couldn't pass that up. 

     

    4/22/2014 5:26 PM  #2

    boomyal
    Senior 24-7 FYI Addict

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    From: Vancouver, Washington
    Registered: 4/01/2013
    Posts: 1,295

    Re: Junk Yard Gems

    Those GT40P heads, inspite of their rather small valves, are the best flowing SBF heads Ford ever produced.  If they had come out with those in the early days of the 289/302 motors, racers would not have had to wait for all the aftermarket heads to beat up the chebbies.

    I have a 2001 Explorer 5.0, with those heads, in my 20 ft boat. That motor is a total screamer compared to the stock 302 that originally came with my boat.  A big plus factor is that with those plugs facing straight out, I can now get a socket on them instead of having to use a box end wrench.

     

    4/22/2014 5:40 PM  #3

    Ron68
    Senior 24-7 FYI Addict

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    From: Mukilteo, Washington
    Registered: 4/01/2013
    Posts: 1,400

    Re: Junk Yard Gems

    Those are the heads (GT40 - not 40P) that I have on my 351W. They definitely have bigger intake and exhaust ports over the stock 70 351W heads I had. Just remember to match the valve springs with your camshaft. I had to switch to stiffer springs because the stock 5.0L springs were too soft and I was getting valve float. I got mine off a 97 Exploder too.

     

    Last edited by Ron68 (4/22/2014 5:41 PM)

    68 coupe - 351W, 4R70W, 9" 3.25 -- 65 convertible - 289 4v, C4, 8" 3.00
     

    4/22/2014 6:03 PM  #4

    ultrastang
    I FYI 24-7

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    From: Camden, Arkansas
    Registered: 4/01/2013
    Posts: 570

    Re: Junk Yard Gems

    boomyal wrote:

    Those GT40P heads, inspite of their rather small valves, are the best flowing SBF heads Ford ever produced.  If they had come out with those in the early days of the 289/302 motors, racers would not have had to wait for all the aftermarket heads to beat up the chebbies.

    I have a 2001 Explorer 5.0, with those heads, in my 20 ft boat. That motor is a total screamer compared to the stock 302 that originally came with my boat.  A big plus factor is that with those plugs facing straight out, I can now get a socket on them instead of having to use a box end wrench.

     
    Yep, if they had only come out sooner....

    The GT40 and GT40P heads share the same 1.84" intake valve diameter. The exhaust valve diameters are different. The GT40 head exhaust valve diameter is 1.54". The GT40P is 1.46" but, higher swirl, higher compression and a spark plug electrode closer to the center of the combustion chamber didn't necessitate a larger exhaust valve.

       •Thread Starter
     

    4/22/2014 6:40 PM  #5

    ultrastang
    I FYI 24-7

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    From: Camden, Arkansas
    Registered: 4/01/2013
    Posts: 570

    Re: Junk Yard Gems

    Ron68 wrote:

    Those are the heads (GT40 - not 40P) that I have on my 351W. They definitely have bigger intake and exhaust ports over the stock 70 351W heads I had. Just remember to match the valve springs with your camshaft. I had to switch to stiffer springs because the stock 5.0L springs were too soft and I was getting valve float. I got mine off a 97 Exploder too.

     

     
    The GT40P valve springs leave a lot to be desired. --for that matter, the stock GT40 springs really aren't that great. The stock 5.0L Mustang H.O. engines with the E7TE truck heads didn't have really radical stock cams. Their lift was rated at .444". Even at this, that's too much for stock GT40P valve springs (it will bind them).

    Stock Mustang 5.0L H.O. springs aren't that great either, though. After 80-90,000 miles they are pretty much used up. A Crane beehive spring set (part number 44308-1) is a very good set, can handle up to .550" lift and is reasonably priced at around $160.00 dollars a set.

    The '90 5.0L H.O. Mustang fuel injected engine I have may very well end up in my '69 F100. I'm not looking to make a major power house out of the engine. I would just like to add some factory items that will enhance it's output over factory stock. I have a 5.0L Cobra upper/lower intake, 70 mm BBK throttle body, 73 mm C & L mass air meter and 24 lb/hr Cobra injectors.  As an option, I could put the tubular GT40 upper intake on that I have.

    ...If that's not enough oomph, I do have an early 1970 ' s 351W with the option of two GT40 lower intakes; a cast iron version from a '95 5.8L Cobra or an aluminum GT40 lower intake from a '93-'95 5.8L F150 Lightning pickup. 

       •Thread Starter
     

     

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