I took my fan along with the rest of my rotating assembly to be balanced. and it turns out that what I thought was a piece of metal inside the steel pulley is a small piece of hard rubber hose.
My machinist said it looks like a piece of small vacuum hose, Did the factory use something like this to balance the pulley? Funny thing is, its laying in a little groove. its pretty peculiar that a stray piece of hose would find its way into my fan blower and just happen to lay neatly into that groove.... I know this engine has never been apart before as I am the second owner.

He said it is 7 Gr out, but if he moves the hose around a couple degrees it goes to 1 Gr. out.

Also the pulley is running .020 out of true

I am thinking to just have him take the rubber piece out and true up the pulley to the fan and see where the balance ends up then. But I think he will have to add some weight there to even things out.
Just wondering if any of you have seen anything like this before.

Don't want to slow him down now since he is finally getting to work on my stuff after a couple months. so I guess I'll take a look at it tomorrow and see what up.

I don't have any pics

They used metal clips, not rubber hose ...

There is a small lip where a piece of wire/rod was crimped into place.

Balance it by drilling to remove weight.