1968-74 Chevy Chevelle LS Swap Mid Length Headers 4:1 3/4 Length Headers Silver Ceramic Coated Primary Tube Diameter: 1-3/4" Primary Tube Gauge: 14 Gauge Collector Attachment: 3 Bolt Flange Collector Diameter: 3" Flange Thickness: 3/8" Bolts and/or Studs Included Gaskets Included Adapters/Reducers Included (must be welded)