Havoline phosphate-free has been my coolant of choice for the last 3 years,
with one coolant change/flush after 2 years.  It has worked perfectly, with
no problems of any sort.

p.s.  The coolant is only used in my 86 Syncro, not in the 73 Super Bug.

Budd Premack
86 Syncro, 73 Super
Minneapolis, MN (Still the Land of Sky Blue Waters)
(It's December, with no snow and open water!  Now I know why the rest of the
hemisphere claims that Fall lasts until 12-21.)