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From what I have read the AFR 165s are better then the Edelbrock but not by huge margin. They are pretty compatible. The one thing you have to note that those heads you have a link to have 2.02 Intake valves so you might have some PTV clearance issues. Also the RPM heads are setup for Roller cams so the springs are stiffer and you have to take that into account.
 

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The Edlbreock 60255 has a combustion chamber volume of 60 to 69 CC. That big a chamber will kill your compression ratio on a 289. I don't know what the AFR chamber is but it's probably smaller than the Edel head.
 

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Discussion Starter #7
From what I have read the AFR 165s are better then the Edelbrock but not by huge margin. They are pretty compatible. The one thing you have to note that those heads you have a link to have 2.02 Intake valves so you might have some PTV clearance issues. Also the RPM heads are setup for Roller cams so the springs are stiffer and you have to take that into account.


I don’t have a roller cam. So those heads wouldn’t work with my current cam and lifters I guess


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From what I have read the AFR 165s are better then the Edelbrock but not by huge margin. They are pretty compatible. The one thing you have to note that those heads you have a link to have 2.02 Intake valves so you might have some PTV clearance issues. Also the RPM heads are setup for Roller cams so the springs are stiffer and you have to take that into account.


The add says he has springs for non roller cams. I think my cam lift is 0.46” so not sure if I’d have issues with the pistons or not. I’m it sure what I have for pistons. I assume “stock”.


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The add says he has springs for non roller cams. I think my cam lift is 0.46” so not sure if I’d have issues with the pistons or not. I’m it sure what I have for pistons. I assume “stock”.


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Unfortunately its more of the cam timing and overlap then it is about total lift. So its something you would have to measure to make sure PTV is good. Also the stock piston valve reliefs are usually not setup for the larger 2.02 intake valve, so definitely measure if you get them. Here is the flow numbers and as you can see they are comparable to AFRs:

https://www.jegs.com/i/Edelbrock/350/60255/10002/-1

And it is a 60cc head. If you decide to get them, i would be interested in the springs if you don't use them. :)
 

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Discussion Starter #10
Thanks guys. I looked it up and I have “273AP” pistons. Also this is the cam I have. It’s basically a stock motor with intake and exhaust.



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Both heads will make the same power. Why? A small 289 with a mild cam is not going to exceed the air flow of either head. Then the other big restrictions to air flow are going to be the induction and exhaust. You can swap valve spring and you can have the heads cut to reduce chamber size to maintain or increase compression slightly.

Here is a good article

https://www.google.com/amp/s/www.hotrod.com/articles/ccrp-1302-six-budget-ford-heads-that-work/amp/

As for me a $275 GT40P Explorer motor moves enough air for for good performance
 

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Unfortunately its more of the cam timing and overlap then it is about total lift. So its something you would have to measure to make sure PTV is good. Also the stock piston valve reliefs are usually not setup for the larger 2.02 intake valve, so definitely measure if you get them. Here is the flow numbers and as you can see they are comparable to AFRs:

https://www.jegs.com/i/Edelbrock/350/60255/10002/-1

And it is a 60cc head. If you decide to get them, i would be interested in the springs if you don't use them. :)
Here are the flow specs for the AFRs:

https://www.airflowresearch.com/165cc-sbf-street-cylinder-head/

AFR flow better up to .500 lift on the intake side and especially flow better on the exhaust side. I like the idea of a smaller intake valve for less plug shrouding.
 

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Discussion Starter #13
I’m worried about the 2.02 valve clearance to piston. That’s why the AFR165 1.98 is more to what I’m leaning to. I don’t want to change pistons. I just think I could get a good deal on these Edelbrock ones. The guy is selling them because they don’t have enough clearance to his pistons.


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Both heads will make the same power. Why? A small 289 with a mild cam is not going to exceed the air flow of either head. Then the other big restrictions to air flow are going to be the induction and exhaust. You can swap valve spring and you can have the heads cut to reduce chamber size to maintain or increase compression slightly.



Here is a good article



https://www.google.com/amp/s/www.hotrod.com/articles/ccrp-1302-six-budget-ford-heads-that-work/amp/



As for me a $275 GT40P Explorer motor moves enough air for for good performance


Thanks. With the explorer option are you talking the entire motor or just heads?


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Thanks. With the explorer option are you talking the entire motor or just heads?


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Either. What's nice about the GT40P head is that is has a relatively small chamber of 60cc. A typical 289 is 54cc. This is about a 1/2 loss in compression with the P head. You can have a slight cut done to bring up compression but the improved air flow will more then make up that difference as you'll be compressing a cylinder that was filled better.

You can either bolt on the heads which people have done or just swap the whole motor. These motors will easily go 300k miles and even a 200K motor will still have the honing cross hatch. With the whole motor this opens the option of a cheap cam swap with the roller tappets. You can reuse them on another cam. Now you can pick up a used hi performance cam fairly cheap from someone who's moved up.

It's something to think about. I'm a fan of the P head as a super cheap head swap but honestly it's still a factory cast iron head and once you start doing any sort of work it's time to think if that money is better spent on a set of aluminum heads. But a set of used P heads in good useable condition can be a great cheap swap! A GT40P will run rings around a typical 289/302. I used the whole motor with a 5.0 cam. It runs very, very well!
 

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I got P heads from a local wrecker for $160. They pulled them.
Got a valve spring kit from Alex’s parts to match my cam profile, $160.
Lapped the valves and did some minor port work myself.
Long tube headers can be an issue. Most will bump against the spark plugs. Found a used set locally that fit although spark plug changes are not easy.
 

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Discussion Starter #18
Either. What's nice about the GT40P head is that is has a relatively small chamber of 60cc. A typical 289 is 54cc. This is about a 1/2 loss in compression with the P head. You can have a slight cut done to bring up compression but the improved air flow will more then make up that difference as you'll be compressing a cylinder that was filled better.

You can either bolt on the heads which people have done or just swap the whole motor. These motors will easily go 300k miles and even a 200K motor will still have the honing cross hatch. With the whole motor this opens the option of a cheap cam swap with the roller tappets. You can reuse them on another cam. Now you can pick up a used hi performance cam fairly cheap from someone who's moved up.

It's something to think about. I'm a fan of the P head as a super cheap head swap but honestly it's still a factory cast iron head and once you start doing any sort of work it's time to think if that money is better spent on a set of aluminum heads. But a set of used P heads in good useable condition can be a great cheap swap! A GT40P will run rings around a typical 289/302. I used the whole motor with a 5.0 cam. It runs very, very well!
Thanks. I get what you’re saying. I’m not interested in a complete motor swap. I just want to upgrade my heads. You’ve peaked my interest with the GT-40P heads. If I had $2k burning a hole in my pocket I’d get the aluminum heads no questions asked. However, being on a budget and my car only being a “weekend warrior” maybe the GT-40P heads are a good option. If I can find some in good condition that don’t need work it would be a cheap upgrade.

What other “catches” are there with the GT40P heads? Intake? Exhaust? Spark plugs?

From my understanding I need to look for 1997-2000 Explorer with 5.0L?
 

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Discussion Starter #19
I got P heads from a local wrecker for $160. They pulled them.
Got a valve spring kit from Alex’s parts to match my cam profile, $160.
Lapped the valves and did some minor port work myself.
Long tube headers can be an issue. Most will bump against the spark plugs. Found a used set locally that fit although spark plug changes are not easy.
thanks for the info. I have long tube headers right now so that may be an issue.

Did you notice an increase in performance with the P heads?
 

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Both heads will make the same power. Why? A small 289 with a mild cam is not going to exceed the air flow of either head. Then the other big restrictions to air flow are going to be the induction and exhaust. You can swap valve spring and you can have the heads cut to reduce chamber size to maintain or increase compression slightly.

Here is a good article

https://www.google.com/amp/s/www.hotrod.com/articles/ccrp-1302-six-budget-ford-heads-that-work/amp/

As for me a $275 GT40P Explorer motor moves enough air for for good performance

There’s a lot more to making lower than how much a head will flow.
 
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