440 head noise. Perpetual problems. Problem solved

I kinda thought it was valve spring related.
My brother had that happen to him years ago.
The next question to ask yourself would be why did it happen?
Are the rest of them far behind in failing?
I'm thinking you should check for coil bind at least and/or wrong valvetrain geometry.
You need to resolve the problem or next time you might not be so lucky, a dropped valve will do a lot of damage.........