D-shaped Port header gaskets designed specifically for Chrysler Gen III Hemi engines, including 2009-2020 5.7L Hemi and 2005-2020 6.1L, 6.2L, and 6.4L applications. These gaskets use a high-temperature expanded-steel core to maintain stability and torque retention under extreme exhaust heat. The graphite-impregnated facing conforms to minor flange irregularities, resists thermal breakdown, and moves heat away from the cylinder head for reliable long-term sealing. High-recovery material helps maintain a seal even if the flange loses clamp load, and the gasket can be trimmed for modified port shapes. Suitable for OE replacement as well as high-performance street, drag race, and oval-track use.