As was stated whats important is the current flow (amps) in the primary ign circuit. Voltage will vary depending on the ballast and coil. Most standard electronic ign systems will see from about 5.5 to 7.5 volts at the coil pos side with the key on eng not running and ballast hot. Remember the ballast will increase ohms as it gets hotter. If you check the volts at the coil pos side with the eng running it is not an accurate way to check the volts because with the eng running everytime the ECU fires the coil it opens the primary coil circuit so the magnetic field will collaspe and induce high voltage in the secondary windings. But everytime the primary circuit opens the volts will read battery volts (12 to 14.5) at the coil pos side because then it is reading an open circuit volts which is not an accurate voltage reading. So when you read the volts at the coil pos side with the eng running you are just reading the average of the volts with the primary circuit closed and current flowing and with the coil primary circuit open and no current flow. The only way to check the volts correct is with the key on eng not running which is the same way you can troubleshoot the primary circuit when you do voltage drop test readings. Bottom line is most of the standard Mopar ECU ign systems will read about 6 to 7 volts at key on with the eng not running on the coil pos side. Thats for a basicsally stock system with a standard ballast. As long as it puts out a good strong spark then that is fine. I use a .75 ohm ballast on my 63 with the orange MP box and an Acell coil and I have turned it to 6500 running 10's and its never missed a beat. Less ohm's in the ballast will give higher volts and more current flow but may damage the electronics if not used right. And of course the MSD systems will shoot 200 to 300 volts on the coil primary circuit and they do work good to keep plugs clean with the multi sparks. Ron