Fel-Pro performance exhaust header gaskets, the performance version of an exhaust manifold gasket, resist blowout and burnout and provide good exhaust flow. Fel-Pro performance exhaust header gaskets consist of a high density fiber facing material attached to both sides of a perforated steel core. This design provides a durable gasket that will seal slightly warped surfaces. Also, we use an antistick coating that allows the gasket to move without sustaining damage and helps the gasket accommodate the expansion and contraction of the head and headers. Fel-Pro designs the exhaust header gaskets with “slotted” bolt holes so you can easily slip the gasket in place and then tighten the bolts. The high density fiber retains the torque to ensure the seal.