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Discussion Starter #1
My 68 289 2 V carb has the stock heads on it which are the worst 289 head you can get.
Would it be worth the trouble to install a set of 66 2v heads on it ? Found a set local that are pretty cheap
GC
 

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GC68, yes, you can and you should. Houston & Super are mistaken. The 66 and 68 289 heads are different, because the early head has 54 cc chambers, while the 68 head has chambers balooned out to 63. Switching from the bigger chambers the the smaller early ones will take you from 8.7 to 1 up to 9.7 to 1. That would be worth it to me. Doing the port matching as described by Awhtx would help you even more. What kind of shape are the 66 heads in ? IF they need a valve job or anything, left me know and we will talk. 351W valves or bigger would help even more ! LSG
 

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GC68, yes, you can and you should. Houston & Super are mistaken. The 66 and 68 289 heads are different, because the early head has 54 cc chambers, while the 68 head has chambers balooned out to 63. Switching from the bigger chambers the the smaller early ones will take you from 8.7 to 1 up to 9.7 to 1. That would be worth it to me. Doing the port matching as described by Awhtx would help you even more. What kind of shape are the 66 heads in ? IF they need a valve job or anything, left me know and we will talk. 351W valves or bigger would help even more ! LSG
Ditto. Even better if they're "non-Thermactor" but even if they are the "bumps" can be ground down. With some modest porting and port-matching and an increase in valve size these can be made to approach aluminum aftermarket heads in flow capability. If "hardened seats" doesn't concern you, remember that SBF iron heads don't have separate valve seats, they're machined into the head so it's just a matter of grinding new seats in the existing heads for larger valves and the guides can also be reamed for oversize stems, although both are not really substitutes for doing it the "right" way and installing hardened seats and new guides.....
 

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With some modest porting and port-matching and an increase in valve size these can be made to approach aluminum aftermarket heads in flow capability.
I don't agree with that. Improved airflow yes but a good quality aftermarket head will flow vastly better. Check out this article. It really does a good job showing the flow of heads from stock to ported to the aftermarket sets. The ported 289 heads made 177 intake 168 exhaust. My base trickflow 11R 170 heads make 266 intake and 204 exhaust. Even the ported 351W heads didn't make that much.
 

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I don't agree with that. Improved airflow yes but a good quality aftermarket head will flow vastly better. Check out this article. It really does a good job showing the flow of heads from stock to ported to the aftermarket sets. The ported 289 heads made 177 intake 168 exhaust. My base trickflow 11R 170 heads make 266 intake and 204 exhaust. Even the ported 351W heads didn't make that much.
"Home Ported" heads with 1.78" intakes and 1.46" exhausts. Note that I said "approach" aftermarket aluminum heads in flow capacity not equal nor account for the wide variation in available cylinder heads.
Small Block Ford Heads
 

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Cg, the factory iron heads, when ported and fitted with 1.94 intakes, flow enough to support 450 hp, if everything else is up to the job. is that enough ? Yes, aftermarket aluminum heads can make more, some of them LOTS more. How much power do you need ? And do you want iron or aluminum heads ? LSG
 

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Discussion Starter #10
LSG & Woodchuck
Picking them up this week for $75 for the pair
Here are the picure he sent.
What do you think
4EF9B641-A072-477E-BF45-8B76BE910DF8.jpeg
5BC5DDEE-4C6B-4B8D-9D1C-A341754DF514.jpeg
F5C36635-C9B8-4937-B3EA-1FA400DC5EFA.jpeg
23E798B6-BC38-4176-A55D-00018B546988.jpeg
 

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GC, small chambers and rail tips, looks like a nice compression boost over what you have. Do the heads need any work, or can you just bolt them on ? What intake / exhaust / camshaft does your car have ? Have you done a vacuum check or a spring pressure check on those heads ? Do they still have thermactor lumps, or has someone already ground them out ? LSG
 

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@Woodchuck I guess I would have termed it differently. I guess my point is that by the time you have paid for the larger, valves, valve job, and a good port an polish (because the average guy will not get that level required to support 450hp), that you are almost in the price range of the lower cost heads. I would evaluate the cost and time vs the cost of new heads. Thats what I did with mine, and decided that I would get new heads. Everyone is different and has a price point.
 

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Discussion Starter #14
GC, small chambers and rail tips, looks like a nice compression boost over what you have. Do the heads need any work, or can you just bolt them on ? What intake / exhaust / camshaft does your car have ? Have you done a vacuum check or a spring pressure check on those heads ? Do they still have thermactor lumps, or has someone already ground them out ? LSG
LSG I havent picked them up yet. The engine is pretty much stock it has 1 3/4 inch dual exhaust on it but I do have a summit aluminum dual plane intake and 600 cfm sitting on the shelf that I am planning to install
GC
 

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GC68, 75$ is decent for the pair. Do a vacuum test on them, and see if they need work. If they're okay, you can grind the lumps out of the exhausts yourself. 64.5 calling them smog heads is a little harsh. Yes, they have Thermactor ports. So, you grind them out. Takes you maybe an hour. You can do it at home.

The 1.75 duals are on the smaller side. Any chance you can upgrade at some point ?

LSG
 

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64.5 calling them smog heads is a little harsh. Yes, they have Thermactor ports. So, you grind them out. Takes you maybe an hour. You can do it at home.
You're killing me Smalls.... Harsh??? They're heads with ports to pump air into them by what's commonly referred to as a "smog" pump, hence, smog heads.
You can grind all you want, but you can't grind out the thermactor ports. If I'm looking to gain performance, I'm not using heads with a hole in the exhaust passage when there are better alternatives.
 

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I'm not using heads with a hole in the exhaust passage .
From the photos it appears that although these heads were cast for the Thermactor system, the holes for the air injectors were never drilled and tapped. The hump is probably inside the exhaust port but it can be ground out with a die grinder and carbide burrs.
 

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64.5, even if the thermactors ports are drilled, one has to tap the holes, installs plugs with Locktite and then carve out the lumps. Yes, If I had a nice pair of C5AE heads, I'd use those. But many of us don't, and the thermactor bump removal takes less than an hour. And most SBF heads need some grinding and shaping in the exhaust anyways. LSG
 
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