GT40 Head question?
05-06-2007, 04:49 PM
#1
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GT40 Head question?
i lookin at gettin some gt40s from the junkyard cuz my e7s are shot. i have the cobra upper and lower intake already. do i need to modify anything or can i just bolt them on? i was thinkin about gettin the e303 cam too. i have bbk unequal shorties too will those bolt up to the gt40s? i dont want the gt40ps i want the ones that came on the cobra as im goin for a cobra look under the hood. any input would be great, thanx in advance.
05-06-2007, 05:11 PM
#4
RE: GT40 Head question?
I dunno if you knew this already or not, but your probably do.
The GT40 heads have 3 lines on the front and the GT40-P heads have 4 lines on the front.
Supposedly the GT40-P heads flow better and produce more horsepower than the GT40's. They can be found in 97+ Explorers.
This probably wouldnt be a bad time to do a little self porting and have the machine shop freshen them up
-Eric-
The GT40 heads have 3 lines on the front and the GT40-P heads have 4 lines on the front.
Supposedly the GT40-P heads flow better and produce more horsepower than the GT40's. They can be found in 97+ Explorers.
This probably wouldnt be a bad time to do a little self porting and have the machine shop freshen them up
-Eric-
05-06-2007, 05:24 PM
#5
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RE: GT40 Head question?
there is no way in hell you will find a cobra in the junkyard with the engine intact.
gt40p's from explorers your headers wont work, longtubes will but shortys wont as the plugs are angled into 2 of the tubes. you will have better luck finding a set of 289 hi-po (car) heads, or early 70's 351w (car) heads. they flow a lil better than the gt40's and they work with your headers, those old heads are usually long gone by now.
gt40p's from explorers your headers wont work, longtubes will but shortys wont as the plugs are angled into 2 of the tubes. you will have better luck finding a set of 289 hi-po (car) heads, or early 70's 351w (car) heads. they flow a lil better than the gt40's and they work with your headers, those old heads are usually long gone by now.
05-06-2007, 05:32 PM
#6
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RE: GT40 Head question?
actually the GT40 heads flow better than the early 351w heads, and the 289 hi-po heads dont really flow better than any other normal 289 or 302 head, it was the cast in spring pockets and factory screw-in studs that made them good heads (and they are worth a fortune).
finding a pre-97 1/2 explorer shouldnt be THAT hard, and again..... everything will bolt right up to them.
ALL 289/302/351 heads have the same exhaust bolt pattern, intake bolt pattern (early 351's had extra bolts which do not need to be used), head bolt pattern, and accessory bolt hole patterns on the front/rear of the heads
finding a pre-97 1/2 explorer shouldnt be THAT hard, and again..... everything will bolt right up to them.
ALL 289/302/351 heads have the same exhaust bolt pattern, intake bolt pattern (early 351's had extra bolts which do not need to be used), head bolt pattern, and accessory bolt hole patterns on the front/rear of the heads
05-06-2007, 06:27 PM
#8
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RE: GT40 Head question?
reason i suggested 289 heads as they have a small combustion chamber so he will gain a little from the compression. the gt40p's do flow better than the gt40's. true if he found an early explorer he could use the heads but hes better off finding a later model and changing his headers as the 69cc chambers on the pre p heads will hurt his compression ratio. the p's and true cobra heads were 59cc (cobra heads were factory milled)
05-06-2007, 07:28 PM
#9
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RE: GT40 Head question?
ORIGINAL: mrbigshot
reason i suggested 289 heads as they have a small combustion chamber so he will gain a little from the compression. the gt40p's do flow better than the gt40's. true if he found an early explorer he could use the heads but hes better off finding a later model and changing his headers as the 69cc chambers on the pre p heads will hurt his compression ratio. the p's and true cobra heads were 59cc (cobra heads were factory milled)
reason i suggested 289 heads as they have a small combustion chamber so he will gain a little from the compression. the gt40p's do flow better than the gt40's. true if he found an early explorer he could use the heads but hes better off finding a later model and changing his headers as the 69cc chambers on the pre p heads will hurt his compression ratio. the p's and true cobra heads were 59cc (cobra heads were factory milled)
05-06-2007, 07:32 PM
#10
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Join Date: Jun 2005
Location: Frederick, Maryland.
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RE: GT40 Head question?
ORIGINAL: mrbigshot
there is no way in hell you will find a cobra in the junkyard with the engine intact.
gt40p's from explorers your headers wont work, longtubes will but shortys wont as the plugs are angled into 2 of the tubes. you will have better luck finding a set of 289 hi-po (car) heads, or early 70's 351w (car) heads. they flow a lil better than the gt40's and they work with your headers, those old heads are usually long gone by now.
there is no way in hell you will find a cobra in the junkyard with the engine intact.
gt40p's from explorers your headers wont work, longtubes will but shortys wont as the plugs are angled into 2 of the tubes. you will have better luck finding a set of 289 hi-po (car) heads, or early 70's 351w (car) heads. they flow a lil better than the gt40's and they work with your headers, those old heads are usually long gone by now.