spark and no spark

My 66 Plymouth service manual suggests 0.2V or less on starter cable, and 0.2V or less on ground when cranking. I would think similar for other years. They also say 0.1V drop at solenoid. They even said 0.3V means poor connection or other problems. That is for stock location.

It is a slippery slope, more voltage drop results in more motor current, more current, more voltage drop. I agree with Del, most drop in +, but both are far from desirable.

I am busy with farm work, or I would be making new cables and changing the starter to mini on my 66 Barracuda. I plan to make a study of it, to determine how to minimize drops..