I was cruising the web this morning and came across an interesting web site that did a study on oil filters for marine applications.
www.oilfilterstudy.com
About 75% of the way down there is a link to the "Grease Oil Filter Study Spreadsheet". This has all the data the author noted in his study....flow rates, pore size, etc., for most major brand filters.
After reading the report, and a lot of the info on this site, I think I will use either the Mobil 1 or Amsoil filter.