I'm still not completely up on the whole grounded-vs-ungrounded thing, but an anode is not a bad idea and should work either way.
The biggest culprit in deterioration seems to be a combination of long flush intervals and especially a bad electrical system overall. If the coolant becomes too much a part of the electrical system and carries too much voltage through it, accelerated electrolysis is the result.
Unfortunately, aluminum just happens to be a more sensitive metal to this process.
Trusted names like Ron Davis recommend grounding the radiator, but I don't remember ever seeing a factory aluminum radiator grounded to the chassis. They might exist, it's just that I haven't noticed any.
I'm sure some will join this conversation with better info, but until then it's not a bad practice to add the sacrificial anode. Whether in the radiator cap or a drain plug, it can't hurt.
Distilled water is good, and you should be able to use any type of coolant you want since you're starting new. Generally speaking though, I would either just continue to use the good old fashioned Green stuff, or better yet one of the relatively new ones that are compatible with all types, and change it every two years (consistently) rather than go to the fancier new high-mileage types. Easier to remain compatible that way, and is safer for when you need a top-off and somebody's only got one type of coolant handy.
You definitely don't want to mix the Green and Orange varieties if you don't have to. And if you do, get it out of there and flushed as soon as you can or you might have a brown gooey mess on your hands.
That's why I say use the multi-brand compatible stuff. Even if it's a little more, it's probably worth it.
The new waterless coolant is pretty neat stuff, but I don't have any personal experience with it.
Paul
