Stripped valve screw

[pr240sx]

What type of tap/die do I need to repair these, I will like to use stock screws if possible. I overtight 2 of them (1 pound extra) because a faulty torque wrench. I had never performed this on any car so any help will be greatly apreciatted

[groundhogday1976]

Do you mean valve cover bolts? If so, which ones? The ones down the middle (in line w/ the spark plugs) or the ones around the edge? If it's the ones in the middle, check this out:http://www.nissaninfiniticlub....37898

[pr240sx]

Thats exactly what happened, overtorqued the screw, stripped the thread. Now I have the screw just sitting there doing nothing!!