Is the D-2 the duraspark? If so, does the vac advance for a '68 distributor work the same way?
Mine seems to work the opposite- CCW delays advance, CW brings it in sooner. Having trouble getting it to not spark knock (even at only 8 BTDC base, and it only does it with vac advance connected and at high speeds, especially under load at high speeds.
Maybe I'm going the wrong way.......