Flames, intermittant spark, missing

How does the ground wire at the battery look? Does it have an aftermarket terminal? The reason I ask is because this gets overlooked quite often. Get a voltmeter and put the positive lead on the engine block and the negative lead at the battery negative cable end, now while someone cranks the engine look to see how many volts register. Anything over 1 volt is excessive and will not allow the ignition pick-up to properly ground and charge the coil for the next ignition cycle and can cause no starts, loss of power, intermittent loss of power, etc. On these older vehicles, and newer ones for that matter, I always verify the integrity of the grounds and proper voltage as well.