For Use With Chevrolet LS Series Engines Except LS7 Installed In 1955-1957 Chevrolet; Engine Swap; 1-3/4 Inch Diameter Primary Tubes; 3 Inch Diameter Collectors; 3/8 Inch Thick Head Flange/ Same As Port (SAP); For Off-Road Use Only; Metallic Ceramic Coated Mild Steel; With Bolts/ Gaskets; Use With GM 605 Power Steering Box/ Hooker Engine Swap Mount Kit Part Number 12611HKR/ Danchuk Engine Swap Mount Kit Part Number 871A For Seam Type Frame Mounts or 871C For Seamless Frame Mounts/ Milodon Engine Oil Pan Part Number 30915