head casting numbers

[Charles M.]

What is the significance of the GM number (the 7 and 16) on my heads? Right side GM7 3782461, date A 5 6 .. Left side GM16 3890462, date D 11 6.

[Harmon C.]

Re: head casting numbers

I belive those numbers are the molds your heads came from at the foundry.

[John H.]

Re: head casting numbers

Those are the foundry pattern numbers that the molds were made from; there were multiple sets of tooling for high-volume parts.

[Charles M.]

Re: head casting numbers

Here is the big question. Can I run these heads together? Are they similiar enough? If i have them ported can they be made equal?

[Clem Z.]

Re: head casting numbers

go to www.google.com and type in the numbers+chevy head and you will get tons of info. just make sure the valves are the same size in both heads because these heads can with different size valves.