91-03 Harley Sportster 1200 Cylinder Head Top End Rebuild Gasket Kit Set 64024. Extreme Sealing Technology (EST) Gasket Sets by Cometic are by far the most advanced collection of gaskets and seals available. The base gaskets and lower rocker cover gaskets feature a nitrile bunadine rubber (NBR) coating on both sides of a stainless spring steel gasket. This type of NBR coated steel gasket will hold its shape and won’t extrude out and fail like the paper type gaskets are known to do under normal cold to hot start ups with rapid expansion. The three piece head gasket design features an aluminized stainless steel center sandwiched between two NBR coated stainless spring steel outer layers. To ensure the utmost sealing power, the outer layers are embossed at the cylinder bore and the oil drain backs providing a seal so good that cylinder dowel O rings are not required. The upper rocker cover gaskets are made from a very pliable rubber that will not harden like OE gaskets do. All other gaskets are made from a Kevlar based fiber material. Fits Sportster 1200 1991/2003. View more great items.