70 up charging system upgrade question

That seems about correct. It should run with lower voltage. It should start with battery voltage.
Remember, once its running, the alternator will be providing system power closer to 14 Volts. The ballast resistor will bring it down from that 14 for the coil positive. How much lower will vary with current flow and temperature. You're in the ballpark.

Charge the battery, get it running. System voltage should be around 14. Maybe a little less at idle and a little more at fast idle.
Then check initial timing, because right now that's seems like a possible reason it didn't want to start easily.

This is a hydraulic lifter engine - stock 318 ?