If you can't document the miles on the timing chain then I strongly recommend you pull the valve cover and look for wear and broken guides and think about changing it.
has a metal backed timing chain guide. A big problem is when the chain stretches it starts slapping the guides and breaks them. The parts get stuck on the oil pump pickup and in some instances the chain will hit the timing cover and wear a hole though at the area the water pump is.
Other then that...RUN THE HELL OUT OF IT!