valve cover stripped stud

i remember as a high school kid you could get a kit that you could in fact put in new threads on existing piece. came with a drill bit to hone out hole and a device to put in the new threads. went to advance to see if available and the guy behind the counter could not understand that this is a common stud. he needed the year and make of the car. told him it was a postwar jeep made by willys and the enigne made by ford and it was a F134 4 cylinder engine. OF COURSE HE GOES TO THE COMPUTER!! AND THEN BRILLIANTLY SAYS DUH WE DONT HAVE THAT IN THE COMPUTER SORRY!!

WENT TO O REILLYS AND BASICALLY HAD SAME EXPERIENCE!!!!

since it on the very end of the rocker arm assembly any one see a reason that it could not go up a size in stud???
or anyone might see or remember the repair thread kit.Attachment 1211

The kit you are describing is called a "Helicoil"kit You need to find a Parts Person. Not a key jockey who couldn't find the blinker fluid jug to save its life.
Back in the hard times of the eighties, we would exchange a stripped 3/8s bolt with a 10mm and tap the hole with a metric tap. Extreme original fanatics will throw a fit at this idea. But when you have to be practical and need to get your baby going, maybe comprise is the answer.