Has the motor jumped timing?

You are describing, what to me, is just a reversed polarity at the pick-up.
Chrysler slanty distributors run in opposite rotation to SBMs; and the magnetic pick-ups are directional-specific.
IIRC
the SBMS have one Orange and one Violet wire.
IDK the colors of the slanty but am thinking NOT Orange
The SBM pick-up can be used by cutting the wires and resplicing in opposite polarity.
I could be wrong.
Looks like I am; See post #29