50/50 mix here too, using distilled water. I run that in all our antique Fords and the coolant is always fresh and clean looking. Not gunky and rust colored like so many I've seen w/o antifreeze and or rust inhibitor
Clunked up dirty coolant killed an awful lot of heater cores from cars I saw being worked on at the local Ford garage in the early- mid 70's. And on Mustangs they were a fit to change, it was not an easy job. Guys used to just bypass the heater core and not run the cars in the winter.
Galaxies were a snap to change, they came out in the engine compartment after removing a plate and the heater hoses
