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For what it's gonna cost to CNC port them - you'd be better off selling them, and buying a contemporary set of aluminum heads. Your flow numbers will likely be better and you'll knock 50 lbs. off the front of the car...
 

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Discussion Starter #3
Perhaps... But that was not the question..
I'm sure there are head porters out there that can exceed the low and mid lift flow numbers of many small port after market aluminum heads.

I didn't raise cost as a factor, but doubt they would be more expensive. You would also get to use better valves, a spring of your choice and have the chambers cut to the size you want.

Here is a connection that peaked my interest in ported GT40's

http://www.corral.net/tech/powerplant/head_tech_4.html

Who's got some good GT40 iron heads out there. ?
 

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I have a set that was rebuilt and ported by Tim over at Jersey Cylinder Head in Pitman NJ. He's a real nice guy, and does tons of work for the dirt track guys over at Bridgeport.
 

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Perhaps... But that was not the question..
I'm sure there are head porters out there that can exceed the low and mid lift flow numbers of many small port after market aluminum heads.

I didn't raise cost as a factor, but doubt they would be more expensive. You would also get to use better valves, a spring of your choice and have the chambers cut to the size you want.

Here is a connection that peaked my interest in ported GT40's

http://www.corral.net/tech/powerplant/head_tech_4.html

Who's got some good GT40 iron heads out there. ?
You'd be wrong. By the time you buy new valves, springs and get them ported you'll be into them at LEAST $800(more likely over a grand) and there are LOTS of used Edels and TFS heads in great shape that you can get for that price or less on the classifieds here.

Ask me how I know.

I've said it before and I'll say it again. GT40 heads are great budget heads but when you start porting them out to flow numbers similar to the big aftermarket production heads they get pricey. For GT40 heads you grind the egr bumps off and MAYBE get them milled. Thats it. Unless you have skills when it comes to porting and alot of time on your hands. Then by all means buy some cartridge rolls and get to work!
 

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Discussion Starter #6
There are cnc porters out there that have pretty credible profiles for E7's
I'm looking for someone with a good CNC profile for a GT40. If any one has had experience with them and perhaps flow numbers to share.

I know about after-market heads. Cost was not an issue raised. If I was willing to invest in used edelbrocks that's what I would get a used set of heads.

I appreciate the answers so far but they are not on point.

Think Stock Appearing Performance....

Anyone out there?
 

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So is this just a new title for the how fast can I go with a stock appearing motor thread?
 

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You'd be wrong. For GT40 heads you grind the egr bumps off and MAYBE get them milled. Thats it.
Any pics here or elsewhere of the egr bumps? I've got a GT40's on my Lightning engine, and would like to clean them up. These GT40's also have the Thermactor holes drilled in the rear, I believe the Explorer GT40's do not. Any value in starting with non Thermactor drilled heads vs. the ones I have?

What is a safe amount to mill off? I'm assuming this is to bump compression? Since I'm probably going to a TFS1 cam, the bump in compression will help with the GT40's I have.
 

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1.Good valves $200-$225 for a set of 16
2. A cnc port job AT LEAST $500-$600
3.Decent springs $100-$200
4. A set of gt 40's to work on around $300

You still need to have the heads worked at a machine shop and possibly add the cost of screw in studs and guideplates, valvejob, and possibly new guides, and also valvestem seals.

Looks like $1100+ easily and still won't work as well as an aftermarket head like afr-tw-edel-etc.

If cast iron factory ford heads are what you must have, then go for it.

But for the same money, you can have better designed alluminum heads that will make even more hp and save weight.

Now if you want to build a high revving iron headed clevor......... thats a whole different animal there.
 

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1.Good valves $200-$225 for a set of 16
2. A cnc port job AT LEAST $500-$600
3.Decent springs $100-$200
4. A set of gt 40's to work on around $300

You still need to have the heads worked at a machine shop and possibly add the cost of screw in studs and guideplates, valvejob, and possibly new guides, and also valvestem seals.

Looks like $1100+ easily and still won't work as well as an aftermarket head like afr-tw-edel-etc.

For me it broke down like this:

Stock 1.84IN 1.54EX valves, 5 angle valve job
new springs, $60 (designed to work with E303 cam)
Port job (intake ports and bowls worked over, exhaust cleaned up, nothing outrageous)
Milled heads to true them, .003" and .005" respectively (no milling done to increase compression)
Cost of heads, $325 complete (1998 Explorer heads)
Stock valveguides were within specification, and I'm using pedestal mount rocker arms, so saved money there.
Cost of all the machineshop work was $665 on the heads, I had him port match an explorer intake too, $150 for that.

I have $990 in my GT40 heads. That's about the limit of what you should put in them, I think. New aluminum heads start about that price, flow better, and weigh less for the price.
 

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Last time I used aftermarkets I bought new GT40P's and worked the bowls,lapped the valves and threw a TFS spring kit at them.Had less then $600 total,which I would consider an iron limit,IMHO.Thumper stressed to me .040 or less milled off the heads will not have intake alignment problems,I cut .035 so I'll know shortly.Street power/torque and track power/RPM are different build theorys,you can take a street car to the track and have fun and be fast,but take a track car on the street and its not very fun.
 

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Think Stock Appearing Performance....
Why do you need to look stock? Unless you're getting the motor inspected for a class event why do you care so much? Hell you can always paint a set of aluminums black and look stock with them too.

I just think its a total waste of money and it WAS in my personal experience.

But hey its your money, if you want to spend $1000 on a set of iron heads that can't grow any more later on down the road more power to you.
 

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Why do you need to look stock? Unless you're getting the motor inspected for a class event why do you care so much? Hell you can always paint a set of aluminums black and look stock with them too.

I just think its a total waste of money and it WAS in my personal experience.

But hey its your money, if you want to spend $1000 on a set of iron heads that can't grow any more later on down the road more power to you.
The man asked for gt40 porting experiance and half the posters have to tell him hes wasting his time and money,any fool with a credit card can whip up something fast.Painting up aluminum heads and installing an explorer intake makes you a poser when you tell people you have stock stuff and made it quick.Its about doing it,not about making it look like you did it.
 

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And its also not a very good investment to put $1000+ into a set of heads that have no more potential just to keep the stock appearance. I still don't get why people care so much if its stock looking or not. And even if it still looks stock it isn't so you're still lying about it.

He can do a search and find a ton of info on porters on here. Thumper is one that comes to mind. BB performance near me also does great work. However they're both going to charge at least $700 for the job. Again not my money but I think everyone here telling the OP not to waste his money is doing it because we've either been there or know someone who has and regrets it.
 

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I always wondered about this too. I agree that you could spend the money for a better set of heads and probably save money, but that's not what he asked. I wouldn't do it, but if he wants to, more power to ya.
 

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And its also not a very good investment to put $1000+ into a set of heads that have no more potential just to keep the stock appearance. I still don't get why people care so much if its stock looking or not. And even if it still looks stock it isn't so you're still lying about it.

He can do a search and find a ton of info on porters on here. Thumper is one that comes to mind. BB performance near me also does great work. However they're both going to charge at least $700 for the job. Again not my money but I think everyone here telling the OP not to waste his money is doing it because we've either been there or know someone who has and regrets it.
Well said..... I have been there and wish I had some of my wasted cash back from some of my bad decisions from the past. If there had been info on the 'net for me when I started in this hobby in 1980, I would have been WAY ahead of the game.

All of the guys here under the age of about 30 don't understand how it used to be. The only info available was through a few car mags(ha ha) and other racers or experimenting yourself.

If you want to spend big bucks on gt40 heads then have fun doing it.But if you are not happy with the performance and need to upgrade again, then expect about a 25 or 30 cents on your dollar spent in return if you sell them and then $1k+ again for better heads.

Sorry if it sounds like I'm preaching, just make sure that ported gt40's will get you to your performance goal before dropping that kind of $ on them.

There is a wealth of info here from many people who have been racing for years. Take advantage of that. There is a HUGE aftermarket of killer 5.0 heads available now. In 1980 I would have loved a set of ported gt40's, but today for that kind of money there are MUCH better alternatives.

Good luck...Dave
 

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if the funds are available then go for it... there is a poster around here dont remeber his name...but he has Stage 3 Ported GT-40'S with a S-Trim i think and is making over 500HP to the wheels...so they can flow.
 

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I have had great luck running DOOE heads with a mild port turned 12.2s with 3.08 gears, Vr Jr on my 84 Mustang. Used to chuckle at guys with aftermarket heads, gears and bigger TBs, expensive tuning.
They are now redone and not fully ported but they flow 235 @ .500 lift and beat stock air flow at every point starting at .1 lift. The runnners are small but air speed is high ith the proper cam more efectively fills the cylinder than the big port aftermarket stuff.
 
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