All cometic head gaskets are 4 layer MLS (multi layer steel). Cometic uses stainless steel for increased strength, it's ablity to rebound and corrision resistance. The outer layers of the gasket are embossed and coated on both sides with a flouroelastomer rubber based material designed to meet the demans of a variety of harsh sealing enviroments, load conditions, and surface finishes. This coating is also heat resistant to 482 degrees F. The shim layers of the head gakset is also stainless steel but is left uncoated and can be varied for a varied thickness. Cometic MLS gaskets are ideal for aluminum or iron surfaces will seal better than any other gasket PERIOD!
*In the event that the 85.5mm gasket is not available we will send out the 86mm gasket in its place. There are no adverse affects from running a larger bore gasket. We have confirmed this by running the 86mm bore gasket on both stock and .020" overbore engines.