The Fueled Racing long tube headers are made with GMPP header flanges and use CNC mandrel bent 1.75 inch primary tubes. The headers are all hand T.I.G. welded and come ceramic coated. The primary runners are internal welded with 70S2 and external welded with Bronze Silica filler. The headers use a 1.75 x 4 to 3inch collector and have 3 inch V band clamps and O2 sensor bungs welded to the collector. These are the same headers that come standard with the complete kits we sell.