Help identify this head please

I am looking at a 360 with this set of heads on it casting number 2858920-6. The owner of the engine does not know much about it as he acquired it from a shop he worked for. He told me the heads are from a 318 but he has them on a 360. I'm not sure about what he has going on. I will probably just use my J heads but I am curious about what the heads are that are on it now. Any help would be great.

Thank you

Brad