E-Core coils typically have half the primary resistance of a typical can coil. They will build more current, and more heat. E-core coils are potted, not oil filled so they can actually fail sooner. E-core advantage is less loss in magnetic circuit, from slug design of can, to a controlled air gap, reducing magnetic path.
Using a HEI ignition module that limits the current to a safe value by hardware and predictive dwell time control, will reduce coil temperature and result in a more efficient ignition.
