Big Block Chevy round port header exhaust flanges. These flanges come as a pair and are designed for 2-3/8" primaries, also these are used only for raised port BBC heads, laser-cut from heavy-duty 3/8" thick 304 stainless steel for superior resistance to warping from high heat, and comes with a limited lifetime warranty.
All warranty questions, claims or otherwise should be directed toward the manufacturer, Dart.
