"Bulletproofing" a Chrysler 2.7, 3.2 or 3.5 liter V6?

The 2.7 had gasket problems in the early years. Chrysler fixed it later. See allpar for more info.
The 3.5 is a good engine. A friend had one in a town & country mini van that went 170,000 miles, loaded most of the time. Still ran sweet until rust got to it.