Well, I grew up around boats in salt water, and bolting zinc's on the shafts and hull (tied to the ground system) was standard. When I put the aluminum heads on, I asked my engine builder. The response was that the new anti freeze compounds will handle that. Almost all modern motors have at least aluminum heads, if not blocks and everything else. But you have to remember to change it. I wasn't told a hard time frame, or any test to run. I think the "manufactures" recommend 3 years or so.

They also sell zinc or something anodes to go in the radiator that are sacrificial.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

My 2 cents, I would think there might be a problem with aluminum heads on a cast iron block but I believe it would take some time. I do know the getting aluminum heads off the old flatheads was a major problem after some years. I can not see a problem with the copper radiators as they don't touch the engine.

Is there a corrosion problem with cast iron blocks and aluminum heads?  The anodic index numbers between cast iron and aluminum is fairly close but they are not the same.  High strength steel numbers are further away from aluminum.  If there is a problem how do we address it.  Special coolant, special head bolts, special gaskets or something else.  Does a copper radiator cause a problem?  The question popped up on a road trip to look at couple of barn finds and I couldn't answer it. The answers will help me pick a radiator for my F-100.