Most of the V8 diesels Mack built went to Australia for their road train trucks, wouldn't pass emissions in the states. They have a few warehoused in Hagerstown Md. I deliver to Mack/ Volvo Powertrain almost everyday for the last 30 years. Oh, and I drive a Mack Pinnacle day cab.
I have never had an HEI module fail on any of my GM cars. But, the first time I took my 68 Cuda out the chrome box died, switched to MSD 6AL no problems in 14 yrs.