I recently got my hands on an 85 coupedeVille. One of the first things I had to do was replace the radiator. I then had the wonderful fortune of a week later the heater core going on me (that was last night) I look on this forum and see all these horror stories about coolant problems and tablets to neutralize pH levels. What I am worried and wondering now is is it safe to put in the Barrs stop leak stuff so I can get to next weekend, and could there be any connection to the the new radiator and now the rest of the coolant system giving up the ghost. The car has extreme sentimental value to me as it was my grandfathers and the engine was replaced 50,000 miles ago so I know it has life left in it. I just got worried that any messing I do with the system might end up in head gasket failure, which to me is a deal breaker. Please send any help that you can.

You'll be much safer if you put BarsLeaks golden seal stuff. It has nothing to do with pH. It just seals minor leaks in the system preventin bigger failures. Change the coolant every two years add the coolans supplement (bars leaks golden seal or GM tabletts) and you should be fine for another 100.000 miles.