Ground problems are old cars worst enemy. I had a problem with my Comet last week. The poor thing sits at the shop and hardly gets run. I'm just too busy to even start it and let it idle for a bit. Well one month prior I was testing out different ignition curve and hit a sweet spot. I (for the first time ever in this car) experienced severe tire hop. Apparently the hop was so bad it shook the ground cable loose at the fire wall. Then a month worth of sitting added corrosion to the loose wire and my used to small battery drain (although this showed me what the power drain was) had only the cooling system to pass a ground through. this motor has only about 10-15 hours of operation on it and, walking by it one morning I heard the distinctive sound of water hitting concrete. The ground plus a battery draw ate a hole in the freeze plug right above the starter. So the thing you should know is, adding an extra ground directly from the battery to the body is not a bad idea. As a mater of fact I don't know why they used to build them without one. 2 Eye connectors, 2 bolts, and about 1-2 foot of wire makes a good electrical insurance plan.
