**Please note: We run a tremendous volume of Cometic Gaskets, please allow 3-4 business days for us to fill your order and have it in transit. Thank you for your patience. MLS (Multi-Layered Steel) Head Gaskets provide maximum sealing performance for today's high horsepower engines and do not require sealants. MLS gaskets are ideal for both aluminum heads and aluminum blocks, and aluminum heads to cast iron blocks. They can withstand the shear force created by the two materials. MLS gaskets have added strength because they are composed of multiple layers of stainless steel; which also creates the rebound ability and corrosion resistance. The outer layers are embossed and coated on both sides with Viton (a fluoroelastomer rubber-based material that is heat resistant up to 250 C/482 F). Viton is designed to meet the demands of a variety of harsh sealing environments, loading conditions, and surface finishes. The center or shim layer is uncoated stainless steel, which can be varied to accommodate multiple thickness requirements. Applications: - Nissan RB25 2.5L Inline 6 - Bore Size: 3.386 in - Thickness: .051"