Cranks but won't start. Unplug ground at field spade on Alternator and it starts?

Put single point distributor in. Timing seems to jump around 3-5 degrees both at idle and when rev'd. But shaft and advance don't have any slack and move freely? Also broke up stumbled on drive with MSD coil swapped in auto parts coil better but still seems like hick up every once in a while and same timing jump around issue. But car seems to run pretty good. Starts very quickly easily.

Saw 14.75 volts at battery after 30 minute drive. And voltage drop between battery and Ign 1 at VR is .2 volts.

I think cars electrical very healthy now. But single points timing jumping around not good. Point gap set to .015 inch. Have a Pertronix Igniter 1 kit coming.

I did a lot of leave key in Run engine off during voltage drop tests and other previous testing. So some of ignition failure could be user error induced.