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

A friend of mine has one of these engines sitting disassembled in his shop for the usual reason: the internal water pump failed, coolant got in the oil and ruined it.

Looking at the block, crank, rods and pistons carefully, this looks like it was basically a nicely-manufactured engine. The block casting looks very nice and the crank, rods and pistons look like they were made of good materials and well-machined.

So I got to wondering if you have ever heard of anybody who knew how to "bulletproof" one of these engines so the water pump wouldn't fail again, and if so, how did they do it? Thanks.