Compatible with 74 Ramcharger/Trailduster: 440, Tube Size 1.75 in. O.D. x 27 in., Collector Size 2.5 in. O.D., Collector Length 8 in., Port Shape: Same As Port; Hooker Competition headers offer the best value in the high performance header market. Designed for the value-conscious buyer who is running either a stock or mildly-modified engine, Hooker Competition headers offer premium features at a very competitive price. Made of durable 16 gauge mild steel tubing, the Hooker Competition header design utilizes a long transition collector to reduce back pressure and increase exhaust flow. A perfect sealing surface is assured with the 5/16 in. machined flanges, with welded O-ring seals.