"I have heard it said that there are plenty of engines running around out there with bearings that are too loose. There are NO engines running around with bearings that are too tight."
That's very filo-sofical ...
Some info. Don't know if it is good or bad. Just sayin.
http://www.fordgarage.com/pages/AERbearinginserts.htm
Rich from AFR doesn't use a filter, according to a video he made.
However, he thinks it is a good idea.
But doesn't recommend a metal timing gear, for reasons unknown.