Join Date: Mar 2002
Location: Austin, TX, USA
Are you running the HEI off the old resistance wire? Usually you would think that lower voltage might make for lower stress. But it's possible that running an HEI module off of a current limited source could cause the failure. For one thing, the positive voltage terminal will be able to ring more than it would without a resistance wire or ballast wire feeding it.
If the resistance wire isn't the golden bullet then I'd start to ask questions about the coil. If the coil is after market then it's possible that it is not well suited for the module.
I believe I was told that NAPA sells a GM ignition module replacement that is a bit heavier duty that stock.
One last thought. If your system voltage isn't regulated well enough, the ignition module may suffer. MSD is one such supplier that is very peticular about the system voltage. That is one reason whey internally regulated alternators are so popular - they do a much better job than the old buzzer box regulator.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI