It's not a helicoil then.
My reasoning: I sent the piece to my builder (Tony Feil of Nascar fame and fortune- yes he normally does Chevys but he did mine and I think Evan's motor as well), he said it was a spring, and It definately lookied like a piece of spring to me.
One think I remember about it was that the spring was filed at one end, just like the ends of the spring in the
oil filter check valve.
I'll check the sandwich plate tonight, double check to make certain there was no spring in front of the cam, and will call Tony Feil tomorrow for some more suggestions.
Intresting isn't it?