A ceramic matrix composite (“CMC”) center body may be positioned around an austenitic nickel-chromium-based superalloy attachment ring. The attachment ring may be integrally formed with a turbine engine case. The attachment ring may have a greater coefficient of thermal expansion than the center body. A plurality of pins may be inserted through apertures in the center body and coupled to the attachment ring. The pins may slide within the apertures, allowing the attachment ring to expand without applying a load on the center body.