97 Cavalier maintenance

I have a 97 Cavalier LS with the 2.4L and 4speed auto. I have put 140000 miles on it with only having the water pump replaced. What should I do in terms of preventative maintenance? Timing belt? Complete tuneup? I have done no modifications to it, I just want it to go many more miles.
J

I would do the Timing chain/or belt. Along with the tentioners. Plugs. Flush trans. Coolant. p/s fluid.