Extreme Sealing Technology Complete Gasket Kit 3,875" Features Every gasket in these kits uses the best materials possible for its intended application Multi-Layer Steel (MLS) head gaskets Steel Viton-coated base gaskets Blue Viton valve stem seals Aluminum Foam Material (AFM) race-style exhaust gaskets Complete kits include motor gasket kit plus primary, derby and inspection cover gaskets Made in the U.S.A. Specs Product Name: Gasket Kit Type: Complete Material: AFM (Aluminum Foam Material) / Viton / Steel Bore Size: 3,875" / 3.875"