GT-40 Irons

91ghp5.0

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May 25, 2005
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I'm looking into some heads that flow better than E7's, but i dont have the cash for thumpers or aluminums...at least that's the way it looks. whoopie for being a college student! do i need to get new pushrods? and are new RR's necessary? what type will i need (pedestal, etc)? lastly...does anyone have a set that has been cleaned up, and what if not what kind of car could i pull them off of at a junkyard to have them cleaned up around here? how can i tell a gt40 iron from say an e7? thanks in advance.

Sincerely...
Broke Student (aka Dan)
 
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You should be able to use the stock pushrods and you will be able to use the stock rockers. I used the stock pushrods with my GT40P headswap and have had no problems but it is always best to use a pushrod length checker and make sure that the stockers will work.

You can pick up regular GT40s off of 93 cobras, first gen lightnings (you will have to use the ARP stepped head washers since the lightning heads are drilled for 1/2" head bolts) and early 5.0 explorers, I believe 96 and early 97.
You want a set of pedestal mount heads, which they should be unless someone had them drilled for stud mount rockers.

Shop ebay and the classifieds as well. They are a good head provided you don't have to put a bunch of money into them right off the bat for stuff like valve job and valve springs. If you can find a set that has already been worked on that would be best.

When I got my P heads here is what I have in them. $275 for the heads( already had a recent valve job) $120 for valve spring kit and $165 for RRs.
 
great site men
Im a newbie here so I thought This would'nt be a bad place to start:)
I have non-p 40's on my coupe, I was in the same boat had to save cash where i could, I quickly found these heads need a good spring to be effective, Mine have minor porting, 3 angle valve job, 1.7 cobra style rockers, with an e-cam, my best time was a 12.70.
With e7's I was in the low 13's with an explorer intake as well, but i think the springs really woke it up....good luck.
 
find out how many miles on them. Depending on milage I would probably look at having a good 3 angle valve job done, possibly put a new set of springs on, I don't know what the springs on the lightning GT40s are rated for in lift, and then put them on. If you want some port work done now would be the time.
 
i do have a set of GT40s.. two sets actually.. ones being ported for my turbo mota and the others are.. well just there.. i know ones good and ones suppose to have a small crack in em.. which they can fix but i didnt really need it.. yours for a whappin 100 dollars plus shippin if required.. not trying to sell you bum heads.. just send em off to the machine shop and spend the money to get em done right with a 3 angle valve job and all that.. regardless of who you get them from.. if your gonna spend the money spend it right
 
RYC CUKR said:
You should be able to use the stock pushrods and you will be able to use the stock rockers. I used the stock pushrods with my GT40P headswap and have had no problems but it is always best to use a pushrod length checker and make sure that the stockers will work.

You can pick up regular GT40s off of 93 cobras, first gen lightnings (you will have to use the ARP stepped head washers since the lightning heads are drilled for 1/2" head bolts) and early 5.0 explorers, I believe 96 and early 97.
You want a set of pedestal mount heads, which they should be unless someone had them drilled for stud mount rockers.

Shop ebay and the classifieds as well. They are a good head provided you don't have to put a bunch of money into them right off the bat for stuff like valve job and valve springs. If you can find a set that has already been worked on that would be best.

When I got my P heads here is what I have in them. $275 for the heads( already had a recent valve job) $120 for valve spring kit and $165 for RRs.




you know, i dont know though. i did some cast iron gt-40's (not p's) and i had to use valvelash caps just to get the roller tip to hit the valve before it bottomed out on the pedistul. so for my heads i needed a longer pushrod, but i guess it really just depends on the work done to the head :shrug:
 
Bad92GT said:
i do have a set of GT40s.. two sets actually.. ones being ported for my turbo mota and the others are.. well just there.. i know ones good and ones suppose to have a small crack in em.. which they can fix but i didnt really need it.. yours for a whappin 100 dollars plus shippin if required.. not trying to sell you bum heads.. just send em off to the machine shop and spend the money to get em done right with a 3 angle valve job and all that.. regardless of who you get them from.. if your gonna spend the money spend it right


where is the crack? any pictures? and how easy would it be to fix something like this?
 
91ghp5.0 said:
where is the crack? any pictures? and how easy would it be to fix something like this?

just send it to a machine shop and let them take a look at it.. they'll give you a price of how much it is... get em to fix it while there doign all the other work i guess :shrug: i was told it could be fixed.. not sure

edit: and its not one of those noticeable cracks.. tiny crack that must cause some kind of dilemma with bolting them on right away.. dont have any pics of them.. both i can include valves and maybe the springs as well if you want them