ok ok, im a freeking pro at this. lol 4 of my 6 head bolts have a heli coil in them now. they actually come with a coil from the factory. but what you need to do is pick all of the old coil out so its nice and clean and get a heli coil set for 8x1.25 if one is bad make damn sure to check all of em, if its at all sloppy heli coil that one as well or else you will be buying another head gasket once that one starts leaking. when i put my new studs in i put locktight in also to help it hold tight. it WILL work.