The original air filter base is a mess since it was drilled off center. This is the best one I could find short of robbing another bike. I had to braze a hole in the middle that I drilled maybe 20 years ago before I figured out that I could use olive jar lids as tops. I used a A1399 base gasket, Wacker 30491 filter clips, 20-6620 15% Ethanol rated Tygon tubing, A1233 choke screws and the original screws that are drilled for safety wire.