Rectangular Port header gaskets for the 1957–1958 Chrysler 392 Gen I Hemi, built with a high-temperature expanded-steel core for stability, strength, and excellent torque retention under heavy exhaust load. The graphite-impregnated facing conforms to small flange irregularities, resists heat, and helps transfer thermal energy away from the cylinder head for long-term sealing reliability. High-recovery material maintains clamp-load even if the header flange shifts, and the gasket can be trimmed for modified port configurations when needed. Suitable for OE replacement, performance street engines, drag racing, and oval-track applications.