An air filter cartridge comprising: (a) a media pack having a rectangular shape with: an inlet flow face and an opposite outlet flow face; a first and second, opposite, sides (330a, b); and, first and second, opposite, ends (334, 335); (i) the media pack comprising a plurality of flutes extending in a direction between the inlet flow face and outlet flow face; and, (ii) the media pack being closed to air entering the inlet face and passing outwardly from the outlet flow face without filtering flow through media of the media pack; (b) a preform shell having: first and second, opposite, sides (354, 355); an outlet end; an inlet end opposite the outlet end; and, first and second, open, side ends (430, 431); (i) the media pack being positioned between the first and second, opposite, sides of the pre-form shell; (c) first and second, opposite, molded-in-place, side pieces (352a, 353a); (i) the first, molded-in-place, side piece being positioned to close the first open side end of the preform shell and to close the first end of the media pack; (ii) the second, molded-in-place side piece being positioned to close the second open side end of the preform shell and to close the second end of the media pack; (iii) wherein the first and second, opposite, molded-in-place, side pieces (352a, 353a) provide for a sealing therein of the first and second, opposite, ends (334, 335) of the media pack and secure the perform shell in position in the cartridge; and, (d) a housing seal arrangement positioned in at least partial overlap with the outlet flow face of the media pack; (i) the housing seal arrangement comprising a seal member defining at least one of an inwardly directed radial seal and an outwardly directed radial seal; (e) characterized in that the preform shell includes a seal frame projection embedded within the seal member; the seal frame projection comprising first and second, opposite, sides; wherein the first and second, opposite, sides of the seal frame projection each comprise a plurality of spaced tabs. (a) a media pack having a rectangular shape with: an inlet flow face and an opposite outlet flow face; a first and second, opposite, sides (330a, b); and, first and second, opposite, ends (334, 335); (i) the media pack comprising a plurality of flutes extending in a direction between the inlet flow face and outlet flow face; and, (ii) the media pack being closed to air entering the inlet face and passing outwardly from the outlet flow face without filtering flow through media of the media pack; (i) the media pack comprising a plurality of flutes extending in a direction between the inlet flow face and outlet flow face; and, (ii) the media pack being closed to air entering the inlet face and passing outwardly from the outlet flow face without filtering flow through media of the media pack; (b) a preform shell having: first and second, opposite, sides (354, 355); an outlet end; an inlet end opposite the outlet end; and, first and second, open, side ends (430, 431); (i) the media pack being positioned between the first and second, opposite, sides of the pre-form shell; (i) the media pack being positioned between the first and second, opposite, sides of the pre-form shell; (c) first and second, opposite, molded-in-place, side pieces (352a, 353a); (i) the first, molded-in-place, side piece being positioned to close the first open side end of the preform shell and to close the first end of the media pack; (ii) the second, molded-in-place side piece being positioned to close the second open side end of the preform shell and to close the second end of the media pack; (iii) wherein the first and second, opposite, molded-in-place, side pieces (352a, 353a) provide for a sealing therein of the first and second, opposite, ends (334, 335) of the media pack and secure the perform shell in position in the cartridge; and, (i) the first, molded-in-place, side piece being positioned to close the first open side end of the preform shell and to close the first end of the media pack; (ii) the second, molded-in-place side piece being positioned to close the second open side end of the preform shell and to close the second end of the media pack; (iii) wherein the first and second, opposite, molded-in-place, side pieces (352a, 353a) provide for a sealing therein of the first and second, opposite, ends (334, 335) of the media pack and secure the perform shell in position in the cartridge; and, (d) a housing seal arrangement positioned in at least partial overlap with the outlet flow face of the media pack; (i) the housing seal arrangement comprising a seal member defining at least one of an inwardly directed radial seal and an outwardly directed radial seal; (i) the housing seal arrangement comprising a seal member defining at least one of an inwardly directed radial seal and an outwardly directed radial seal; (e) characterized in that the preform shell includes a seal frame projection embedded within the seal member; the seal frame projection comprising first and second, opposite, sides; wherein the first and second, opposite, sides of the seal frame projection each comprise a plurality of spaced tabs.