The 1967 Plymouth Barracuda 383,
Utilized a Carter AFB {Model #4298} which was a small-jetted AFB.
The 1 7/16" Primary x 1 9/16" Secondary unit was rated at 525 CFM's with
the smaller Jets, not 575 CFM like the other early AFB's mounted on the 383 engines.
If you enlarged the Jets by (.010), you could achieve a boost in performance.