Head Stug Leakage

[my4dv8]

Forget the o ring idea , very much doubt it will help at all. Best idea is to pull the suspect stud out ,thoroughly dry out the offending holes slather the very clean stud and hole with loctite #3 non hardening sealer .and as an extra help you could grind up a seal well block and add it to boiling water to dissolve it and then add it to a warm radiator to allow it to circulate.