John, are there rules in posting a reply? If I've broken any please excuse me.

But just so you can un bunch your undies John (don't want to cause a rash ).....

Here's what I do. Nothing, clean them, install them, paint them like factory.

There are no brush on coatings like RPM that I am aware of that will withstand exhaust manifold temps enough to prevent rust on a plain steel part, Maybe Jet Hot or some type of ceramic coating but then what's the point? That said if you only drive the car sparingly in nice weather the cleaned and painted factory stuff will probably stay pretty nice for a long time. If you want better results then you'd likely need to replace them with aftermarket bolts made from a rust resistant metal.