There was an extensive discussion on this a few months ago with a lot of good information. Suggest you do a search. The majority of the extended life
antifreeze/coolant is not compatible with many of the silicones & elastomers used the "high performance" gaskets that we tend to use . The long life coolant was designed for the newer vehicles (to prevent boilover) that normally operate at much higher temps but have compatable gaskets.
Rick