questions about my heads

[Slik69]

I have 462264 no cast into my heads and according to the chart they are 75-86 year head. But my heads are stamped 70 on this insude..and have a single trianle between cyl #2./4 It's really been a challenge trying to figure out what heads these are.

http://www.frontiernet.net/~ennis/castingno.html

Could the years listed just be incorrect. I don't see how something that's stamped into a head could be wrong.

[too much stuff]

If the casting number is 462624 they are 75-86 350 or 400 heads. car or truck. They were not available in 1970. If you are reading the date code, it is probably 7-0 (july 1980) If they have the steam holes they would be from a 400.

[Slik69]

Where are the steam holes located. Also they say 70 in the upper portion of the head near the intake, not 7-0. I have seen many heads and jsut assumed that that was the year as it is with most other heads. I was also reading late last night that there were service replacement heads with the same cast no., but that does not make sense either because of the 70 that's stamped in them.

Apparently the service replacement heads has thicker wall casting. I'm stomped. There are some smaller no's that I cant hardly read. Should I try and see what those are. They are the date numbers i believe.

[too much stuff]

There will be some smaller holes between the combustion chambers if they are 400. The date code will be something like I-28-0 for example. I don't know what the 70 stamped in there means. You will have to go by the casting number and date code. It can be broken down more from there. Do yours have an extra exhaust mounting hole? (where the manifold bolts up?)
As far as replacement heads having a thicker casting? I am unsure of that one.