the weird thing about face book marketplace and I don't know if its just me. The search engine sucks and always throws in rando things along with what I am actually looking for. I typed that listing title word for word and it never popped up in my search. the link you posted worked fine.
I know, I know. Hard to find. I have found two passenger side heads but no luck on drivers side. I have all the time in the world so I can wait. I would prefer not ported, but not going to be picky.
Finally back in a Mustang and looking to restore some things. Looking for a set of FR 500 cams and heads. Even better if the heads are ported by Fox lake. I am in no rush and these will probably be hard to find but I have time.