Do you need to isolate an aluminum radiator?

i think grounding your aluminum rad is a no no.You don't want current flowing.
Frame and aluminum are the dissimilar metals and the coolant is the electrolyte.
Most cars had the rad grounded from the factory and that ground should be rem'd.
you can install a sacrificial zinc anode from an outboard.The problem usually occurs
if you use high mineral content water in your cooling system.
..this is just stuff i have read...who knows?