I have a Van's air filter on my RV-9A with a Lyc O-320-E2D and it fits good. Yes it is slightly off center to the pilot's side but it does fit. I have approx. 5/8" clearance on that side and have not noticed any marks on the cowl after 20 hours of flying time. Also this will put the air intake off centerline but again it has not posed a problem. Good Luck! ---- PTP