HKS Metal Head Gasket (0.7mm): 2003-06 Nissan 350z HKS metal head gaskets are constructed from multiple layers of steel to ensure proper head to block sealing under the most demanding high performance conditions. In the construction of each HKS head gasket, a special metal which is extremely resistant to the severe levels of both heat and corrosion, that is attributed with high-horsepower and high-boost conditions, is used to ensure gasket integrity. Aside from the durable internal construction, all HKS head gaskets are also coated with a special fluorine rubber coating to provide the ultimate sealing. HKS head gaskets are designed to accommodate for oversize pistons and altered compression ratios. For certain applications, multiple gasket thicknesses are available to change the dynamic compression ratio according to the needs and characteristics of the various levels tuning and engine conditions. HKS gaskets are not designed to cure sealing problems caused by head or block irregularities. These Gaskets are the HKS Stopper Type gasket which is HKS's most effective gasket as it consists of the maximum layers of plates possible for the best possible sealing and durability. The increased sealing capability is also due to a molded stopper ring around each combustion chamber. Bore: 97mm Compression Ratio: 10.3 Thickness: 0.7mm