The First 1967 383 A-Body, 'Barracuda or Mr. Norms's Dart'

OK,

I'll see if I can post photo's with the difference in the slight shape design improvement
between the early 1966 casting exhaust manifolds and later 1967 casting exhaust manifolds.

As a side note. Notice how Mopar produced the 1968/1969 '383' Intake Manifold with
1 11/16" x 1 11/16" Primary and Secondary throttle bore openings on the manifold.
This allowed you to install a 750 AVS (off the 440) without any manifold
modification.