Thankyou to both of you. I have been using purified water and adding a water pump lube anti rust. It appears that Peenray products are the way to go. I have the 2000, but was concerned that I should be using 3000 because most of the responder’s seem to use 3000. I have good flow Into the radiator, what frustrates me Is when I Idle, waiting to be In a local community parade, I begin to overheat. I have not used the 2000 yet but plan on doing so. I drain the radiator every fall and the water comes out the drain very clear.