.... An easy fix is to get the next size larger "standard size" stud and retap the head.
This may be described as an "easy fix" for some, however in my experience drilling and tapping and inserting new studs or helicoils into a 30-year old 22 head while on the engine was extremely difficult to do correctly.
![Blah blah :blah:](https://board.marlincrawler.com/Smileys/marlin/blah.gif)
But... I am not a machinist, engine builder, nor auto mechanic.
![Gap :gap:](https://board.marlincrawler.com/Smileys/marlin/gap.gif)
Gnarls.
![Driving :driving:](https://board.marlincrawler.com/Smileys/marlin/driving.gif)