Filter cartridge arrangements and assemblies; preferred features; methods of assembly and use

A filter cartridge comprising:

• (a) pleated filter media surrounding an open filter interior;
• (i) the filter media having first and second ends;
• (b) a first end piece positioned at the first end of the filter media;
• (i) the first end piece having a flow aperture therethrough;
• and,
• (ii) the first end piece including a radially directed housing seal member thereon;
• (c) a second end piece positioned at the second end of the filter media;
• (d) the filter media first end defining a first media outer perimeter at a location adjacent the first end piece;
• and,
• (e) the filter media second end defining a second media outer perimeter at a location adjacent the second end piece;
• (i) the first and second media outer perimeters being eccentrically aligned with respect to one another;
• and
• (ii) the first media outer perimeter, defined by outer pleat tips, has a first dimension of length and the second media outer perimeter has a second dimension of length, the first dimension of length being within 90-110% of the second dimension of length.