Mallory Hyfire Ignition problem

It's a 690 part # branded as Mallory.

Sounds like something is getting hot, expands and opens the circuit. Cools off an it's good again. I've had a Hyfire-6al in my Dart for almost 20 years and it's still going strong. They do take specific coils.

My coil is mounted on the intake, I'm kinda wondering if the heat is the problem. What coil are you running?