No hardened seats. Pretty much like 302 standard heads, not much potential when you consider what else is available out there. The only stock Ford heads commonly available that are any good are the 1969/70 hi-po's, C9OE and DO0E.
Of course, if they are all you have, some port work will make anything better. If they have the thermactor bump in the exhaust port, grind it away. You won't have the greatest top-end power, but at lower revs like a street engine they can be made to work. I ran a set like that, "soft" seats, for 100K miles with no problem.