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Discussion Starter · #1 ·
I know there are date code numbers underneath the valve cover that will give me a date heads were made. But is there any way to tell what I have from the numbers on the outside?

Block is a 1971 302
Heads: passenger side has the number 33 near the #1 spark plug hole and a #6 on the top rear corner near valve cover.

The driver's side head has the #6 at the front top corner near valve cover and the #25 or 26 at the rear near (just behind) the last spark plug on that side.

Have searched for a long time but have only found a reference to a 289 HI PO head with numbers 19,20,21 on the outside corners.

BTW the heads have 1:6 rolloer rockers, screw in studs and a spring seat machined in. There is also a guide plate on them. It is a pedelstal style, no rail. And the roller rockers look like the old style with double nuts on top. And there is what appears to be a letter P with a circle around it in the center of the head, it has a raised surface

ANY IDEAS I'm beat can't find anything. and don't remember date code
 

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They are not GT40P heads. Those have GT and P in the corners outside the valve cover. The valve covers will have to be pulled to get any decent info, including the casting dates in the little circle 'clocks' and anything else in there. The closest you could get as they have been modified, is early or late heads by spark plug size. That's not much. Pull the covers. What do you really want to know?

David
 

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Discussion Starter · #4 ·
Yeah they are not GT40p the spark plug holes are the larger size and are angled.

What I really want to know is what these numbers mean

Heads: passenger side has the number 33 near the #1 spark plug hole and a #6 on the top rear corner near valve cover.

The driver's side head has the #6 at the front top corner near valve cover and the #25 or 26 at the rear near (just behind) the last spark plug on that side.

I did not realize all the information about the head was coded on the top end. I thought I actually had to pull the head and look at the bottom end to get the head I.D. number

Thanks for the help.
 

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I did not realize all the information about the head was coded on the top end. I thought I actually had to pull the head and look at the bottom end to get the head I.D. number.
No, the real answer is bottom and some top, with the casting number on the bottom and date info and other clues on the top inside the VC along with other info sometimes. Since you were not pulling the VCs to get dates, I figured you wouldn't be pulling the intake either. ;) OK so you have large plugs, and that makes them pre-'75. If you're lucky, pulling the VC will tell you if they are 289, 302 2V, 302 4V or 351, as that is often cast into them. With the VC off you can check the date and tell which it is by that (sometimes). And of course, other clues. Note that they would not be pedestal prior to '78. Anyway, I understand the numbers on the corners are simply multi-piece casting mold and assembly numbers, so if they get bad casts, they know which mold parts it came from. So, what number did you find on the bottom?

David
 
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