Hedman Hedders has been manufacturing quality headers in the USA since 1954, and classic musclecars is their specialty. Each set uses mild steel, smooth flowing, CNC mandrel bent tubes, that are hand-welded to ensure each pair is identical to the next. Hedman's unique, gasketless ball and socket collector design allows your Big Block Chrylser's exhaust system to bolt up, even if it is not perfectly aligned with the header collectors. This set is part of Hedman's BLACK ELITE line of headers that uses stout 3/8" flanges, and thicker 14 gauge primary tubes. The heavy-duty construction of HEDMAN BLACK ELITE Hedders makes them ideal for high-performance engines, which produce higher exhaust temperatures. BLACK ELITE models have a SATIN-BLACK ceramic finish that can withstand temperatures up to 1400 degrees F. The coating looks great, and keeps more heat in the tubes, resulting in faster exhaust speeds to improve exhaust scavenging, and reduce underhood temperatures. These headers fit both manual and auto transmission models, however, modification to shift linkage may be required. The smooth 1-3/4 in. tube design provides excellent exhaust flow to let your 361-440 (wedge-style) engine breathe deep to produce maximum horsepower and torque. Each set includes a pair of gaskets, header flange bolts and collector bolts. No collector gasket is needed. Hedman Hedders is so confident in the quality of its headers that these headers are factory backed by a Limited Lifetime Warranty. The ceramic-metallic coating is covered by a 5-year factory warranty, in addition to Hedman's standard lifetime header warranty.