[johnneilson]

I would not be alarmed if this is all you found.
It looks like alum, hard to tell. Could it just be some debris from the oil filter mount where the line fittings were tapped?

If you are really concerned, send a sample of the oil out for analysis. This is where you can find out what is wearing by the concentrations of different materials. Make sure to inform the lab of all the information you know about the motor, insert bearings, aftermarket pistons and the rings used.

If that was a bearing, you would have already known it. The motor would have stopped long before you had a chance to look in the filter.

One parting note, I would consider using another brand filter if that is a Fram.

John