1980 DOHC stripped out spark plug... how to repair?

[spencer Johnson]

I heli-coiled #2 plug but I don't like the feel of it.  It felt too loose and I think it is going to blow out again.  I will find out soon.

In preparing for a possible fix again, HOW SHOULD I GO ABOUT REPAIRING IT THE RIGHT WAY?  Can I do it myself (some kind of kit?) or will I have to take it into a machine shop?

[Re-run]

Well normally a helicoil will work fine. The install might have been less than perfect if there engine were in the frame though. Hard angles to work at.
You could do one of these. Might be a bit more robust than a helicoil.

[spencer Johnson]

What are you referring to when you say "you might try one of these..."  I was looking for a link or some kind of reference to another type of procedure.

Thanks for helping.  I am looking forward to getting this on the road before good spring weather arrives.