Ceramic Coated Headers Designed for: 318 Polyspheric or Poly engines 62-67 B-Body. Tube size: 1-3/4″ O.D. Collector size: 3.0″ with 3.0″ 3-bolt flange. Flanges: 3/8″ thick, laser-cut, contoured for a leak free fit.For more details visit the TTI Website.Price does not include shipping. FOB from Corona, CA 92880-1726 . Shipping can be very expensive depending on your location. For an accurate shipping rate please call us.