Remove the distributor cap. A common problem is pinching the pigtail for the pickup coil to ignition module. It's the one that plugs into the back of the module on the inside of the distributor. Check to see if it got pinched and shorted by the distributor cap. If so, insulate the damaged wire, twist the connector so the wires wrap around one another, then reconnect it to the back of the ignition module.
Also check that the little carbon contact button is in the center of the distributor cap.
Next, look at the connectors inside the ends of the ignition module harnesses. They should be positioned equally from the end of the plug. Sometimes they hit the module pins and get pushed back enough that they don't make contact. At the same time, make sure the 2 harness ends are seated down on the coil.