#4448308 heads have any potential?

You need to have the heads looked at.

If the guilds are in fact bad replace them. Its needed for a tight valve seal that last.

5 angle valve jobs are not needed. Sure the heads might flow a bit more but guilds and a normal 3 angle valve job will last a long time and still flow ok.

I would skip the 2.02 intakes unless the intake valve need to be replace-unlikely.

Same with harden seats. Even heads without any type of hard exhaust seats will last a couple of years before the valves sink.

So I would have the heads disassemble and new guilds and a performance valve job and new springs and retainers-locks too.