can i use gt-40p heads?

natestang5.0

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May 10, 2006
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I found a set of gt-40p heads are they any different than the gt-40 heads. They were off of a 98 or 98 explorer. Are they any better or worse ,power, strength and so on? Thanks
 
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To put it short, they're the best iron production heads Ford ever put on a 302. Yes you can use them, but you'll need either MAC full length headers or MAC "P Head" specific headers, or of course Ford's own GT40P headers, because the spark plug angle prevents typical headers from being used (actually, most times you can use them, but you'll have to unbolt your headers from the heads just to change plugs....which sucks).
 
boss 302 heads are completely different.. there not even 302 heads.. the proven best heads were the very rare 53cc "J" heads offered on 302s in 67.. very rare heads.. some of the best flowing.. if your talking new tech then yes gt40p is the best
 
sbftech said:
boss 302 is far better so is the 2vcc aussie head on the 302c, no there not the same

Boss 302 heads are old tech, high maintanence and at least a little over rated. Besides, can you go out to a junkyard and pick some Boss heads up? :lol: Honestly i think if you took an Explorer motor and built it to the same compression and cam specs, i think the GT40P heads would make more power. It would need a better intake but if you could both engines with a carbed setup with identical intakes and carbs, i bet the P heads would outperform them. If the Boss heads were really all that, they would have stuck with that design.
 
Bad92GT said:
boss 302 heads are completely different.. there not even 302 heads.. the proven best heads were the very rare 53cc "J" heads offered on 302s in 67.. very rare heads.. some of the best flowing.. if your talking new tech then yes gt40p is the best
sure they are 302 heads, there different from the cleve heads and the aussie 2vcc head that came on a million 302's are far better than a gt40 dont car what anyone says.
 
I guess to avoid an endless debate about old school heads that you can't even find anymore, i should have said the best heads that you can reasonably find. I can't really say for certain that they're better than anything in Australia because even if they're better, i can't go out and get'em and even if i could there's probably some differences that would prevent them from being used (they use the '00 Cobra R heads on production cars over there, but they're a bit different).
 
85_SS_302_Coupe said:
Boss 302 heads are old tech, high maintanence and at least a little over rated. Besides, can you go out to a junkyard and pick some Boss heads up? :lol: Honestly i think if you took an Explorer motor and built it to the same compression and cam specs, i think the GT40P heads would make more power. It would need a better intake but if you could both engines with a carbed setup with identical intakes and carbs, i bet the P heads would outperform them. If the Boss heads were really all that, they would have stuck with that design.
ya your right, splayed canted valve heads are overrated :rolleyes: Gee what iron canted valve head is banned from almost all forms of sanctioned drag racing? That damn overrated canted valve head :rlaugh: You build me your best 302-306 with gt40 heads and I will do the same with a canted valve head, tuck your tail and run
 
sbftech said:
ya your right, splayed canted valve heads are overrated :rolleyes: Gee what iron canted valve head is banned from almost all forms of sanctioned drag racing? That damn overrated canted valve head :rlaugh: You build me your best 302-306 with gt40 heads and I will do the same with a canted valve head, tuck your tail and run


Are you running those heads in your car? Can you easily and affordably build an engine with those heads? Are we in Australia? Are there Australian 302s laying around in every salvage yard around your house? Man c'mon, like i said if they're so amazing then why isn't every aftermarket head maker out there copying that design? It was a good idea in it's time, but it is out dated, no two ways about it. Any modern aftermarket head has a million things going for it over those heads. We aren't comparing them to the aftermarket, but the GT40P heads are closer to aftermarket heads than your typical E7s are. Oh yeah, can you pass emissions with Boss heads?
 
85_SS_302_Coupe said:
Are you running those heads in your car? Can you easily and affordably build an engine with those heads? Are we in Australia? Are there Australian 302s laying around in every salvage yard around your house? Man c'mon, like i said if they're so amazing then why isn't every aftermarket head maker out there copying that design? It was a good idea in it's time, but it is out dated, no two ways about it. Any modern aftermarket head has a million things going for it over those heads. We aren't comparing them to the aftermarket, but the GT40P heads are closer to aftermarket heads than your typical E7s are. Oh yeah, can you pass emissions with Boss heads?

exactly.. my dad has serious connections in ford and he MIGHT be able to get a set of heads.. thats if hes lucky.. thats after 22 years and tons of favors between reps and all.. all hes trying to say is production heads.. in the US.. thats like arguing the fastest car in the US is a production car in Europe.. when there arent any to begin with here
 
85_SS_302_Coupe said:
Are you running those heads in your car? Can you easily and affordably build an engine with those heads? Are we in Australia? Are there Australian 302s laying around in every salvage yard around your house? Man c'mon, like i said if they're so amazing then why isn't every aftermarket head maker out there copying that design? It was a good idea in it's time, but it is out dated, no two ways about it. Any modern aftermarket head has a million things going for it over those heads. We aren't comparing them to the aftermarket, but the GT40P heads are closer to aftermarket heads than your typical E7s are. Oh yeah, can you pass emissions with Boss heads?
OK now since you changed your criteria of the best production head :rolleyes: The aftermarket caters to people who can barely turn a wrench let alone figure out to build a motor with a canted valve head, I thought you were smarter than that. Take the "old tech" antique iron 4vcc cleveland head, junk huh? When done right will hang with any readily available aftermarket head that 99% of people are going to buy and bolt on. Has nothing to do with old tech, a canted valve head is superior to an inline head, dont care what anyone says. I digress, the GT40 is the BEST production head ford ever used on a 302:nice:
 
Bad92GT said:
exactly.. my dad has serious connections in ford and he MIGHT be able to get a set of heads.. thats if hes lucky.. thats after 22 years and tons of favors between reps and all.. all hes trying to say is production heads.. in the US.. thats like arguing the fastest car in the US is a production car in Europe.. when there arent any to begin with here


Right....i guess i'm just a little too preoccupied with "reality" because i have never, and i probably will never live to see a Boss 302 in a Fox body Mustang, for all those reasons i listed above. My interpretation of "best" includes all these things, not necessarily which makes the absolute highest peak hp. Another thing, the Boss heads didn't even come alive untill the higher RPM range, and they peaked HP in the 8k+ range....now who the hell is running those kinda of RPMs on all motor 302s anyways? On the street those heads would suck. Christ, the intake valves were somewhere in the 2.20 range, so unless you built one for forced induction or you've got a short block that's bullet proof enough to run 8k RPM, what's the point?

GT40Ps are the best production because they're pretty easy to come by, they use current style roller rockers/intake/exhaust setups, and the range of use is more realistic than Boss headed 302s.
 
sbftech said:
OK now since you changed your criteria of the best production head :rolleyes: The aftermarket caters to people who can barely turn a wrench let alone figure out to build a motor with a canted valve head, I thought you were smarter than that. Take the "old tech" antique iron 4vcc cleveland head, junk huh? When done right will hang with any readily available aftermarket head that 99% of people are going to buy and bolt on. Has nothing to do with old tech, a canted valve head is superior to an inline head, dont care what anyone says. I digress, the GT40 is the BEST production head ford ever used on a 302:nice:

LOL, i bet you're from that Boss 302 era huh? Also, maybe you're missing the "P" that i'm sticking on there every time....
 
85_SS_302_Coupe said:
LOL, i bet you're from that Boss 302 era huh? Also, maybe you're missing the "P" that i'm sticking on there every time....
No not really, i grew up with my dad who worked in fords drag racing program on the clevelands, he was a low key behind the scenes guy that very few people knew about. He was paid cash and kinda was like the marine that gets sent on a special mission, if you get caught by the enemy (ford management), we dont know you and cant help you. So I have alot of experience with canted valve heads and I am partial I guess.
 
Oh just another little sidenote, watch this years engine masters contest, notice the abundance of canted valve cleveland heads:D Not that it's releveant to the issue at hand but the canted valve is where it's at.
 
sbftech said:
No not really, i grew up with my dad who worked in fords drag racing program on the clevelands, he was a low key behind the scenes guy that very few people knew about. He was paid cash and kinda was like the marine that gets sent on a special mission, if you get caught by the enemy (ford management), we dont know you and cant help you. So I have alot of experience with canted valve heads and I am partial I guess.

Yeah man, they're badass, i'm not trying to take away from them, but they're just not realistic by today's standards, even if it can be argued that they are better. Sometimes on a forum you don't state things as clear as they could be, and i guess it's only a matter of time (seconds) untill someone from the 100k members replies about how terribly wrong you are..lol