Header Leak??

Well bad news...I got one header on and all torqued up, but the other one stripped a bolt hole :/ the bolt is out and the header is off, what should I do about that? It just the first little bit of the hole, not the whole thing. Tap it to clean up the threads?

It said to torque them to 20 foot pounds, that seemed a bit excessive for the aluminum heads, nothing else got stripped besides the one hole, should I reduce the torque?