What is the best coolant for a 1982 307 engine ? one site says the 307 needs the old style 2 year green coolant as it has better lubricant for the water pump . The older green coolant is not that common any more . I now have the 5 year long life Prestone in the 307 . Just put it in as the water pump had to be changed . The water pump was not leaking but bearings were grinding and loose . So now i am wondering did the water pump fail do to having the wrong coolant in engine . Last water pump had only about 9000 k on it , but car was in storage most of that time. And was a reman pump . Should i put in an additive to increase lubricant ?