Top end gasket kit includes correct base, head gasket and cylinder O-rings as well as other top end specific O-rings or seals needed for R&R of top end. MLS head gaskets promote an even torque load across the gasket sealing surface, providing less bore distortion and better piston ring seal for more power. 4-stroke head gaskets are made to perform on today’s highest-output 4-stroke naturally aspirated and boosted machines, utilizing a multi-layered steel design with the outer layers being embossed and coated with a Viton rubber coating; these head gaskets are designed to meet the demands of today's high-horsepower, high-cylinder-pressure engines. EST (Extreme Sealing Technology) gasket kit includes embossed stainless steel head, base and rocker gaskets covered with a proprietary rubber material. Head gasket material allows heat to be drawn away from the combustion ring and dissipated evenly across the gasket surface to eliminate hot spots and gasket failure. Made in the U.S.A..