Join Date: Dec 2001
Location: Belleville, Illinois
Thanked 22 Times in 17 Posts
If your ignition came with a ballast resistor it will work without it, but not for very long. The ignition system is designed to run on about 11 volts. The resistor cuts down the running voltage from 14.5 to the designed-for voltage. There's a terminal on the starter solenoid that supplies direct battery voltage to the ignition system, bypassing the resistor, when the engine is cranking and the battery voltage is pulled down by the load. If you bypass the resistor and feed running voltage to the ignition system the balance between the coil and the condenser is changed, and the points burn out quickly.
As for what you might have on the back of the carb, if it's down near the bottom of the carb it's probably for the vacuum advance. I can't think of anything else that a '68 would have such a fitting for. Some carbs had a large fitting for a 3/8" or 1/2" hose to feed the brake booster, but more commonly in that era they plumbed a fitting directly into the intake manifold.
Where abouts in Illinois are you?