the valve cover gets 7# of torque. it took a hell of a lot more than that to do what you show in the picture. to answer your question, if there are any threads left in the deeper area, you can remove the broken parts and clean up the remaining threads. if not, you may be able to build it up with some jbweld, or other similar "cold metal" and tap it. since it only requires 7# it may work out for you.