A cover plate for use in a cabin air compressor is a generally cylindrical body with 19 holes extending through the body and an inner bore defining an inner diameter centered on a center axis. The body has a thickness in a dimension measured perpendicular to the central axis. The inner diameter is 14.840 inches (37.693 centimeters) plus/minus .005 inch (0.013 centimeter). A diffusor housing, a cabin air compressor and a method of replacing a cover plate are also disclosed.