Remflex Exhaust Manifold Gaskets Cadillac 425-500 , 1968-1979 # REM14-001Remflex Exhaust Manifold Gaskets Cadillac 425 500 , 1968 1979 # REM14 001 Header Gasket, Graphite, Square Port, Cadillac, V8, Set Port Style: Square port Gasket Material: Graphite Port Height (in.): 1. 688 in. Port Width (in.): 1. 688 in. Quantity: Sold as a set. Remflex Exhaust Header Gasket Sets Remflex exhaust header gasket sets feature 100 percent flexible graphite construction that's effective up to 3,000 degrees F, far exceeding any vehicle's