You probably can use a helicoil on the head which will give you the same size as you currently have. The helicoil tap is larger than the bolt size so that you can thread the helicoil into the head. You drill it out to the size specified, use the helicoil tap, insert the helicoil, bend the tab, and you are good to go.

If you do it right, you have steel on steel and you won't ever have a problem again.