I have figured out a retro fit for replacing the oil bath air filter on my 57 super 88. I purchased a WIX #42043 filter (11.035 X 3.5). It fits pretty good but I wasn't sure if it made contact with the top. I bought "Frost King" rubber foam weather seal self stick tape 3/4X7/16X10 at the local hardware. I stuck the weatherseal to the bottom of the new cartridge and it raised it up so I am sure of a good seal. Cost about $15.00 total.