Intake manifold is it stock..which gaskets to use

No recoat after?? Or few coats before you bake it??.. I think my wife would let me bake it...she is into cars!
the reason I warm it up first, is to evaporate whatever moisture may be deep in the rough cast surface first, before you paint. Some people might use a metal etch primer, too. That's what I would do, but I don't know that it's necessary.