Intake Manifold Gasket Ultra Seal Intake Gasket Ultra Seal Intake Gasket; rectangle Port Shape; Port Dimensions W-2.23 in. x H-2.60 in.; SPECIFICATIONS: Engine Make/Size: Ford Big Block Material: Ultra-seal Packaging: Retail Port Shape: Rectangle Position: Upper WARNING CA Proposition 65: No FEATURES: Nitrile Rubber And Fiber Will Not Crack Or Split Resists Wicking Withstands 600+ Temps Silicone Bead Around Port Creates Tight Leak proof Seal Nitrile rubber and fiber. Will not crack or split and resists wicking. Withstands 600 plus degree temperatures. Silicone bead around the port creates a tight leak proof seal. Using his own '57 Chevy as a rolling test bed, drag racer Joe Hrudka launched the most famous gasket company in the world more than half a century ago. Building a name for himself and his company competing at Cleveland-area tracks Norwalk and Dragway 42, Hrudka quickly established Mr. Gasket as the go-to gasket source for racers with a line of head gaskets, exhaust gaskets, oil pan gaskets, and fasteners that sealed perfectly every time and withstood the punishing temperatures and pressures of racing. Now an important part of Holley Performance, Mr. Gasket continues to expand application coverage with more and more new products for race cars and muscle cars alike. Beyond the gaskets that made the Mr. Gasket brand what it is today is an endless variety of high-performance parts, including carburetor and fuel system components, chrome-plated accessories to dress up your engine bay, fuel additives, shifter accessories, cooling-system accessories, specialty tools, and a wide array of heavy-duty suspension and driveline components.