Performance Composite-Steel Back Head Gasket for 396-427ci Mark 4 Big Block Chevrolet. Bore Opening 4.320″; Thickness .040″
Material: Graphite-Kevlar with Steel Back & Fire Rings. Copper Coat sealant recommended for steel back side of gasket. This high performance head gasket is made of three elemental components; graphite-kevlar body mechanically clinched to a perforated steel core with steel-backing & fire ring armor. This allows for a strong but compressible gasket which will not damage aluminum cylinder heads from fretting or friction brinnelling. Recommended for use on naturally aspirated engines up to 12:1 compression ratio. Package Contents: 1 piece.