HEI in Mopar ECU casing

In the 3rd picture from the top, the TO-220 tab transistor is show. It replaces the fake TO-3 package transistor. The insulating pad under the TO-220 is shifted, and may likely be the point of failure. There is approximately 400V, between the tab and case, I doubt the insulator was doing its job. The 400V transient at ignition event, may arc to case, around edge of insulator.