X Head Help!!!!

Ok, I've got a great running 340 now that I've sorted out a million little problems. A potentially large one has just showed up and I need some opinions. Someone along the line of previous owners has stripped out the very front passenger side exhaust manifold threads. The ones that plug of the #@%*ing water jacket in the heads. Do I a) heli-coil it or b) tap it out to the next size and drill out the flange on the headers or am I c) screwed and buying new heads?