The First 1967 383 A-Body, 'Barracuda or Mr. Norms's Dart'
1967 A-Body 383 'Exhaust System'
Due the 'pretzel-shaped' exhaust manifold (driver side), as everyone knows it restricted exhaust flow.
The original exhaust pipes (primary) leading to the mufflers had numerous 'flattened areas' to clear the under-carriage.
Some sections were smaller than 1 7/8", which was smaller piping than the 'intermediate' 383 2-Barrel exhaust piping
on the 1967 B-Body cars (ie; Satellite and Coronet).