Frank, and all.

The fact that ethylene glycol, as a base, with a mixture of corrosion
inhibitor's, will prevent electrolysis from occurring, in a cooling
system, regardless of the dissimilar metals.

It is when the DCA level drops in the coolant, and this allows the
metals in contact within the cooling system to be attacked by
electrolysis.

I highly doubt that an "H" fitting with  relatively small dimensions, or
inner surface area, all by itself, will cause any catastrophic results.

It would more than likely be caused by a zero PM program by the
vehicle's owner / driver.

Keep the coolant's PH correct, no electrolysis.

Pretty simple concept.

Later,

            ______________
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     ~~~ ~||-(())----(())-|

Terry--
74 Campmobile- (Clementine)
85 GL- (Delilah)
86 BMW 325 ES- (Eva)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     "In life, it is much better to want
something you cannot have---

Than to have something you can't get rid of"

(T.K.)