I've never had much luck retorquing a head once the gasket started leaking. There will probably be some soot from a combustion chamber on the sealing surface. Maybe you will be lucky. A person deserves to have good luck every once in a while. I would sure watch it closely. I'm sure you know what happens when anti freeze gets in oil. Even if you do have to pull the head again, its not going to be an all winter project nor will it be that expensive.