66 Dart still surgeing.Electrical??

Have you tried free revving it up to the stutter?
It's a bit dangerous due to the fan, but if you have a tach, rev it from inside and get the reading, retard the timing some, then rev it to the rpms where it last stuttered, if it's less, or goes away, either the distributor's advance mechanism is faulty or you're running poor quality fuel.
A severely worn timing chain or loose pump/distributor shaft bushing will cause timing issues, too.

BTW, have you checked the vacuum readings, yet?

Mark.