[dmjlambert]

Generally speaking, HEI was not put into cars and trucks by GM until the alternators went to internally regulated. And the distributor power wire was not routed to the starter any more to provide the full 12V during start, because HEI distributors were not powered by a resistor wire.

Since you can't know for sure what caused your module to fail, all you can do is improve the conditions it runs with, to make them more favorable or modern. So, that means upgrading to a 12SI or CS130 alternator and remove the external regulator, making sure the distributor power wire is not tied to the starter solenoid like it was from the factory, and replacing the old coil with a good one, perhaps an ACDELCO one from Rock Auto or have a local store like O'Reilly order one if all they want to give you immediately across the counter is their store brand. Other general tune up things like replacing the spark plug wires and distributor cap, if it has been a long or unknown time for that, would also be a good idea.