Not sure of this topic has been beat down yet, but a search didn't pull anything up, u less I didn't search right. Anyway, I need to replace the oem coolant in my 03 GP with the 3.1. Pretty sure the oem dex cool is still in it. I pulled the radiator cap yesterday and on it was a thick brown substance that could be pulled off like old gasket material. What's the correct type of coolant to be run in these to replace the oem acidic dex cool? Should I also do a full system flush?