[MaSnaka]

DocDirk,
I may have the same air filter you have (oval w/1 3/4" tall K&N element). My problem is the top of my air filter sits right on top of the choke horn on the carb. Not much clearance around the choke horn for any air to get through the primaries with the air filter assembly installed. The top breather design may solve the problem, but it's really the allowable hood clearance that restricts what we can use. My day at the chasis dyno was all for not once the air filter went back on for the final pull. But I was educated by it. Now I know. Still working on the solution.

John