Polished Ceramic Coated With A Thermal Barrier. 2-1/4″ 426, 472, And 528 Headers With Coil-over Suspension. Designed for: 67-76 A-body. Primary tube size: 2-1/4″ O.D. Collector Size: 3.5″ With 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.