Not an Expert, Yet I am a mechanical contractor, and even basic water heater hook ups, Steel take water fitting to copper house pipe, you must install dialectric fittings to stop corrosion,
I have seen sacrficial anodes in radiator caps as well as same on out board motors to prevent aluminum failure on outboards,
What is recommended when using Aluminum heads and even aluminum radiators, ( forgive typing, Im 63 an cantr see to well )
Thank Guys