1970 Firebird Std Duty Exhaust system was outfitted with 2″ head pipes 2 1/4″ over the axle pipes with 2′ tail pipes. Our Firebird Exhaust systems have been reproduced from originals and come with the correct head pipes with correct flats, correct over axle pipes, correct tail pipes with exact original bracket welded on, correct transverse muffler, GM style clamps, installation instructions, diagrams and sealant. Reproduction cast flanges, muffler hangers and tail hangers are available with our systems. Ask about our concourse show package for those of us who like the restoration to be a little more real than real, and our reproduction Pontiac clamps.