Spark plug, head thread problem

[BuickMan]

I got a tune up a few weeks ago and the mechanic informed that one of the spark plugs was bigger than the other five. Apparently the previous owner screwed up the threads on the engine head and used a healer coil with a bigger spark plug. The mechanic put in the regular spark plug with healer coil and it keeps popping out. I never had a problem with the previous oversized spark plug. Is there a way to fix this besides getting the head replaced? Can I use another oversized spark plug and healer coil?

[Robby1870]

Well, if what you say is the case, there's no way to make the correct size plug fit without replacing the head. I would just put the bigger size plug in and gap it correctly to match the other 5. If you really feel like doing it right, re place the head. The job is pretty straight forward on a 2.8L

[White93z34]

you could buy another heli-coil kit and atempt to get one to thread into the existing heli-coil so you could run the proper spark plug.

[patgizz]

did he put in the same size plug as he took out, or stock one?

 

if the latter, put in the size he took out(which i'm sure he threw out)