Remflex GM V8, Big Block Chevy/GMC 454 / 502 Exhaust Manifold Gaskets # REM2030Remflex GM V8, Big Block Chevy GMC 454 502 Exhaust Manifold Gaskets # REM2030 Exhaust Header Gaskets, Graphite, Irregular Port, Chevy, Big Block, Pair Port Style: Irregular Gasket Material: Graphite Port Height (in.): 1. 875 in. Port Width (in.): 2. 000 in. Thickness (in.): 0. 125 in. Quantity: Sold as a pair. Remflex Exhaust Header Gasket Sets Remflex exhaust header gasket sets feature 100 percent flexible graphite construction that's effective up to