Cobra heads
- Thread starter jg22
- Start date
blksn955.o
Founding Member
Depends on what your goals are. Dont expect much but if you got them for around $200 and get them cleaned up for under $150 it wont be too bad. Dont expect to end up with the same results if you went with say AFR 165's or TFS fast as cast heads or something.
FWIW with box stock take off 95 cobra heads, TFS1 cam, ported stock lower gt intake, no tune I went 13.5 @ 102 with a crap 2.3-2.4 or something 60ft on $80 regular street radials (best 60ft on those tires was 1.93 or something).
Check out the 300rwhp gt40 thread.
Useless no, there may be a better route but if iron gt40's fit your needs, take off's are better than stock E7's.
FWIW with box stock take off 95 cobra heads, TFS1 cam, ported stock lower gt intake, no tune I went 13.5 @ 102 with a crap 2.3-2.4 or something 60ft on $80 regular street radials (best 60ft on those tires was 1.93 or something).
Check out the 300rwhp gt40 thread.
Useless no, there may be a better route but if iron gt40's fit your needs, take off's are better than stock E7's.
WhiteCobra95
10 Year Member
- May 2, 2006
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If you have the time and talent, the iron GT40's do well ported. But like everyone says, there are significantly better aluminum aftermarket heads out there if you have the money.
The production iron heads can make good power with very well matched combos. A good friend of mine built an '86 302 with ported iron GT40's, '94 cobra cam, 1.7:1 rockers, long tubes, 3.27 rear, FM GT40 intake, t5, and ran 13.2's @ 104 with wheel spin through first and part of second in his '86 convertible. That was with a mostly stock suspension and the late 90's BF drag radials.
The production iron heads can make good power with very well matched combos. A good friend of mine built an '86 302 with ported iron GT40's, '94 cobra cam, 1.7:1 rockers, long tubes, 3.27 rear, FM GT40 intake, t5, and ran 13.2's @ 104 with wheel spin through first and part of second in his '86 convertible. That was with a mostly stock suspension and the late 90's BF drag radials.
alleymad95GT
Member
Your post is implying you are going to buy GT40p heads??? Why would you do that??? You already have the GT40s...unless they are broken or something...
If you want iron heads and are happy to know that the absolute best you will ever get out of an N/A combo based on stock parts is right around 300 rwhp, use the ones you already have...
Also, FWIW, I would steer clear of the letter cams...you can do better than the E cam...your stock cam with 1.7 rockers is better than the E cam, IMHO...
Just my two cents...
WhiteCobra95
10 Year Member
- May 2, 2006
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I have to agree. For the money you would spend on a ready-to-run set of GT40P's, you could probably find a shop to CnC your E7's (or at least you can in MI) and do a lot better across the board on torque and power. Some people like the GT40P's since they're usually cheaper than other performance heads, but I would put the same amount of money into the E7's or the GT40's you already have before I would invest in P's.
BTW: My friend's convertible weighed in around 3,300 w/o driver, ran 89 midgrade (because he was cheap about fuel), and had a really good tune/calibraiotn with an 80mm MkVIII MAF and 24 lbers. We estimated about 330 at the flywheel and around 300 at the wheels. He added 400lb crane valve springs to spin it just shy of seven, and put nearly 100k miles on engine doing that. There's something to be said for finding a happy combo of stock parts (or production based parts) that work well together for saving money and adding some durability.
Good luck with your build, those are some tough choices
BTW: My friend's convertible weighed in around 3,300 w/o driver, ran 89 midgrade (because he was cheap about fuel), and had a really good tune/calibraiotn with an 80mm MkVIII MAF and 24 lbers. We estimated about 330 at the flywheel and around 300 at the wheels. He added 400lb crane valve springs to spin it just shy of seven, and put nearly 100k miles on engine doing that. There's something to be said for finding a happy combo of stock parts (or production based parts) that work well together for saving money and adding some durability.
Good luck with your build, those are some tough choices
99FiveOh
15 Year Member
Of course if you are planning to huff some air into that motor the GT40 irons will be right at home.
Curious, do the 94/95 Cobra heads have the thermactor ports in the exhaust ports? I know the set of P's I got from a late exploder didn't have them. I know for sure that's a big power killer, you can't even get your finger into the exhaust ports with the smog ports in there!
Curious, do the 94/95 Cobra heads have the thermactor ports in the exhaust ports? I know the set of P's I got from a late exploder didn't have them. I know for sure that's a big power killer, you can't even get your finger into the exhaust ports with the smog ports in there!
blksn955.o
Founding Member
Cobra GT40's have the ports. Also the non P's can be ported further due to the P's having the water passage closer.
My thumper ported exh. ports I like showing off.
My thumper ported exh. ports I like showing off.
99FiveOh
15 Year Member
pwcracer
Founding Member
I had the cobra GT40's on my old setup and was shocked at how much boost I lost when I switched to a cheap set of performers (Better flow). On the plus side I was able to sell the GT40s rather quickly to a guy that wanted them for a stock class race car.
hollywoodstang
Active Member
- May 23, 2006
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Cobra GT40's have the ports. Also the non P's can be ported further due to the P's having the water passage closer.
My thumper ported exh. ports I like showing off.
I bet these heads have more then a grand in it. I like Iron better on the street then aluminum heads. It's cool too, lol
blksn955.o
Founding Member
I got a big hookup from Thumper but the work would have been in the $650 ballpark (same cost as he charges for E7 work). I already had springs on the heads spec'd out for the TFS1 cam and up to 1.72rr. I had paid for a spring, valve job, mill, cleaning refresh a year or so before Thumper got them and that refresh was REALLY close to what Thumper charges to refresh and port...since he also mills, does a valve job, and as you can tell not only cleans them but paints them.
Honestly, even if the gains were only marginal to unported...cost wise might as well ship to have ported and refreshed if the end cost is going to be not too far off from having them refreshed alone.
These heads and the 175 shot put me well within the power range to break a lot of things...and just under the block splitting level, maybe even enough to split the sucker if I get greedy. That is enough for me and the irons fit my needs.
Honestly, even if the gains were only marginal to unported...cost wise might as well ship to have ported and refreshed if the end cost is going to be not too far off from having them refreshed alone.
These heads and the 175 shot put me well within the power range to break a lot of things...and just under the block splitting level, maybe even enough to split the sucker if I get greedy. That is enough for me and the irons fit my needs.
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