HEI modules are known to WORK ...or NOT WORK! no in-between...no warning.....Thats why it is usually the first thing folks go to when the ignition fails. Check all connections (little ground wire in center of the 3 wires going to the coil
and then DRIVE IT.....use it....make it earn your trust back by USING it. Yeah its a hard thing to NOT trust if this is a 10 minute run to the grocery store or....2 hrs cause it will not restart...
OR
Spend $150 replace everything in/on dizzy ....move on