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

The first run of 2.7 engine did not have large enough oil drain back hole in the cylinder heads. Also the PCV system was not adequate so the engine would sludge up badly. You would have to change the oil about every 2000 miles to keep it clean. Also they have a timing chain that looked like a small bike chain that would stretch bad enough to set camshaft timing codes. The later engines the cylinder heads, intake, and timing chain were all redesigned. It was better but still had the water pump leaking problem. Also you can not new use any of the updated parts on the older engine because when they changed the timing chain design they went from an SBEC to the JTEC engine controller and the camshaft sensors are not compatible. It will always have a cam/crank sensor out of sync. Ask me how I know about that one! If you see a 2.7 engine under hood my advice is close the hood and run away!