If all you need is some zinc grounded to the case, why not replace the coolant drain screws with galvanized screws?

Bill

>Well, I was once a chemist, but not anymore.  But I do know that zinc
>has a higher electrochemical potential than the iron and
>aluminum/magnesium alloys found in our engines.  That means it more
>readily donates its unpaired electrons in solution than the others, and
>is consumed first.  Hence, the term "sacrificial anode."  This forms
>zinc salts, and I can't imagine them causing any problems with the
>coolant.

>I wouldn't expect to get any more than the recommended two years out of
>standard coolant however, because as the normal acids form the zinc will
>be "sacrificed" quickly.

>The zinc should be grounded to the case, and that is how the $50/pair
>Z-Sticks from FGA work.  They are supposed to replace the water jacket
>drain plugs on each side of the case. Kinda pricey, but probably worth
>it.