A few times lately that I've had my 1970 'Cuda out the engine will just randomly shut off just driving down the highway. No sputtering, just engine off like I cut the ignition. I coast to a stop, look under the hood and see nothing disconnected. I get in and turn the key and the car starts and runs perfectly. This has happened a few times. I hate not being able to trust the car. I have the Mopar Performance electronic ignition, no orange box, I have one of Ehrenberg's black boxes that is sold on ebay. Seems fine, good ground etc... Could this be a faulty coil?