I was wondering if in need to us the seal that comes with the K&N ? Do in need put that on the UPD upper air box lid?
Thanks

 

Yes and yes to your questions. The K&N rubber seal isn't as thick as the ones that come on paper filters. I would put it on just to make sure dirt doesn't get by the seal. That way you'll only have to worry about dirt getting through the K&N. I don't use one, I don't think they're worth the money and the worry about their filtering effectivness.
Jim