The voltage regulator controls the alternator which controls the output voltage, NOT THE BATTERIES.
The early and late A-4's were even shipped from the factory with a ballast resistor. Once you convert to an EI the resistor really becomes necessary for a happy coil as the "dwell" which charges the coil is a far longer elapsed time between pulses.
Neil and many others did a lot of work to get coil killing under control. That work has been verified many times over. My advise is to listen to him or Tom at Indigo
.
The block will not work as a heat-sink as it is not in any real contact through the coil clamp.
Dave Neptune