Ford 460 Remflex 3018 Exhaust Manifold Gaskets Square Port 1988 1998 # REM3018 Rate_10 low rise design with a 180 degree low rise design with a 180 degree firing order greatly improves torque over a wide rpm range for excellent throttle response from off idle through 5500rpm which are 15 Remflex exhaust gaskets come in a standard 1 8 inch thickness and are designed to crush 50 percent allowing them to fill any pits or gaps in the flange surface up to 1 16 inch The aluminum cylinder head and steel header or manifold combination are configurations that readily cause gap issues in the mating flanges due to contraction and expansion of the dissimilar materials