When does money outweigh sentimental value? 1968 notchback build thread

Been through the Dexcool dance many times. My Mom and Dad bought an Impala SS brand new in 1996 and they had to have the radiator and heater core replaced twice under warranty. I flushed it all out and went back to normal Prestone green after the warranty expired, and the car had no cooling issues for the next 20 years....