What are these stock heads?

[Boss 351]

I can't figure out what they are. I have this "9D29" and "WCP" where the valve springs are and the numbers "25" on top, outside of the valve cover area. The heads are cast iron and from a 351W. The windsor also has the letters "WCP-13" on the block? What the hell is this? lol I can not find any info at all.

Thanks.