No problems, there is no secrets there. There is a support bearing and a seal. I use a sealed bearing and the lip seal is on the inside. I couldn't find a bearing that was rated for crank RPM (Max I could find was 10000 RPM), so my line of thinking was that if the bearing died, the seal would stop crap getting into my motor.
To fit I bore out the center of the stator cover and drill the the stator hold bolt holes all of the way through and finish tapping them. My support bearing then bolts into these holes from the other side if that makes sense.
