Remflex 2007 Exhaust Gasket for Chevy V8 Engine, (Set of 2) 1-1/2 inch width x 1-5/8 inch height Large D Shaped Port; Chevy V8 - SB 262, 265, 267, 283, 302, 305, 307, 327, 350, 400, Large D Port, Brodix, Headers, 2/Set Fits Brodix Track 1 Cylinder Heads Port configuration comparable to Fel-Pro 1406 Heating and cooling of the exhaust system causes header and manifold flanges to warp resulting in gaps between the head and header which Remflex exhaust gaskets seal completely due to the thickness and compressibility of the 100 percent flexible graphite There are no rubber binders or composite materials in Remflex exhaust gaskets so they will not shrink or harden due to time or temperature eliminating the need to go back and continually retighten your flange bolts