That is probably what made the stock coil run so well, then quit.
I am using an internally voltage controlled ICM that does not require the resistor, so I removed it. Full system voltage to coil at start and idle, but reduced as rpms increase. This is with a stock coil, no problems.
IIRC, the TFI coils do not require the resistor. You may have a bad ICM that is overdriving your coil and burning them up. Also, failing parts in the ignition system can lead to damage of the ICM.
The ICM really should have a dedicated ground, a poor ground can damage coils as well as the coil grounds back through the ICM.
I am not familiar with the CRT system, but it is vulnerable to the same maladies that cause similar ignition systems to fail. What distributor, ICM and coil are you running now? What are you using for a heat sink on your ICM?
Carter BBD feeding 4.2 Nuttered 6 banger = 22 MPG Hwy
If it was easy, everyone would be doing it.