Leaking Thermostat Housing. Thinking on billet with O Ring

Going back to last year's post.... I was reading up on the Dexcool/OAT problems a few months ago and ran across this interesting info:

The Dexcool OAT coolant problem is from air getting trapped or entrained in the coolant. It reacts with the air and then does the 'gunky thing'. Corrosion in the 'green stuff' is entirely different and HOAT coolants do not have a this issue either..

Some problems that bring this on :
- Leaks in the coolant recovery system that lets air in the cooling system
- An old system with no coolant recovery system that has to have an air gap at the top of the rad
- Here is the big surprise problem which has caused problems in some engine and not in others: Water pumps cavitating. This goes to the heart of the water pump and cooling system design and in some case cannot be cured.
- Localized boiling that can put air bubbles in the system. This helps push towards more AL heads and will happen more if you have weaker cooling system

Ford has stated that part of their reasons to drop certain engines in the last few years was due to the cooling system design simply not being able to work with these OAT coolants. With the desire to put in 10 year no-change coolants from the factory, which the OAT's are good at, the engine cooling system designs have to be right, and must be changed or scrapped if they cannot work without cavitation or localized boiling.

And Mopar has switched to the OAT's in the CTD's now and I assume other engines.

I'll probably stick the green and the HOAT's (like G05) since they can be mixed and I don't know which old engine design is air-free and which is not.