my truck was rebuilt at 260k and a engine shop owned the truck at the time. a person who i will call "joe" bought it and sold it to me at 325k. joe was driving it and one of the hoses came off and over heated it a bit. not too bad though. oil started to mix in the coolant and he changed the oil cooler. didnt fix the prob. he said head gaskets were next. i bought it and did the head gaskets and replaced one of the heads. didnt fix it. water pump went out and radiator was cracked. replaced and fix those and now it haves a brand new oil cooler on it. i lost count on how much antifreeze and oil i put into it.