Are 586 small block heads any good?

Only problem with LD 340's is everybody thinks their gold. When I was a kid they were about all there was on the used market so I've run a many of em. The problem now is they have reached that legend status that makes everybody think they are worth a fortune.If I picked one up for $50 I would use it. I will probably use whatever is dual plane and cheap at the swap meet because almost any basic manifold will work.I only gave $100 for this set of heads at the Mopar nats a few years ago and they are brand new from Chrysler(not remans) I probably wont have but $500-$600 in this whole motor including the sanderson street rod headers.