Timing question

20160828_085608.jpg I have attempted to time my '65 slant 170, all stock except for Pertronics EI. I have rotated the distributor counterclockwise as far as it will turn in an effort to retard the timing.
The timing is still reading way above 15 TDC, and the car really hesitates when accelerating.
It does run well otherwise. How can I dial it back more?