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Discussion Starter #1
Well, my 66 is back with a freshly rebuilt 428. She runs AWESOME and I could not be happier.
Alas, I don't know what heads he put on and nor does he?! They are larger so to drop the compression to a more manageable ratio but I can't find any information online to help in ID'ing them. The only marking is a very obvious 7H. I have checked the usual sources and the only ones which might say 7H are even smaller than the stock heads.
There is reference to 6X 7H heads. Is that what is on there?
As always
Thanks
I will try and attach a pic
 

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1973-'74 4X heads having the 7H stamping. The 7H head combustion chamber is 98cc. Used on 400CI with automatics. Large 2.11" intakes/1.66" exhaust. Heads came with either press-in or screw-in studs depending on production year.
 

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"...The only marking is a very obvious 7H. I have checked the usual sources and the only ones which might say 7H are even smaller than the stock heads..."


Is it possible that the number is 7H1, and the 1 is just not readable ?

The 7H1 heads are '72 350 heads, which do not have the pads for the end exhaust manifold bolt holes, and have press-in studs. Some ID sites show the 7H1 heads to have 80cc chambers. Some guys say most Pontiac chambers are actually larger than advertised. So, I don't claim to know if this info is correct or not. Just passing on the link to one of the head ID sites.

Alamo Area Chapter of the Pontiac-Oakland Club International (AACPOCI)

"...There is reference to 6X 7H heads. Is that what is on there?..."

6x heads have a very obvious number, cast over the center exhaust ports. There is a listing for 4x-7H heads. The 4x is cast over the center exhaust ports, and the 7H is stamped on a small vertical pad(pictured below). And, both the 4x & 6x heads have all 6 exhaust manifold bolt holes drilled and tapped. :)
 

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Whats the date code on the heads? That should help narrow it down. I had 7H1's on my Lemans, 91cc chambers, 1.96/1.66 valves, and like Oldskool said press in studs and no exh manifold end bolt holes.
 

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Discussion Starter #5
codes

The date code is E242 cast at night. Head code is strictly 7H with no 1 following. All codes are clear and easy to read.
Thanks again.
 

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That head is obviously a 7H1. I don't know why the 1 is not on it. You can see that the 7H is off center. If you add a 1, in the correct place, the 7H1 would match the 7H1 in the 1st two pics below, don't you think ?

Notice in the 3rd pic, that the 2-digit 6H is centered over the exhaust ports. I think that if Pontiac had cast a 7H head, they would have centered the 7H over the center ports.

In the last 2 pics are a 7M5 & a 7K3. Notice how the 3 digits are fairly centered over the center exhaust ports. :)
 

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I'm with oldskool on this one as well after seeing the pics. However, the 7H1 heads have a different casting with a raised boss encompassing it whereas the 7K3 heads don't and look much more as the 7H in the photo. Is it possible these heads were cast a different foundries and thus the difference in the casting numbers?
 
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