Flowtech Headers Chev LS Universal Engine Swap # 11575FLTFlowtech Headers Chev LS Universal Engine Swap # 11575FLT Headers, 4 1 One Piece, Stainless Steel, Natural, 3 Bolt Flange, Chevy, Small Block, LS Engine, Pair Header Style: Long tube one piece Header Material: 304 stainless steel Primary Tube Outside Diameter (in.): 1 5 8 in. Header Color: Natural Flange Style: Standard Weld Up: No Cylinder Head Port Shape: Round Collector Attachment: 3 bolt flange Collector Diameter (in.): 2. 50 Collector Reducers