Ford Taurus preventitive mantainence

I have a 2000 Ford Taurus with 203,000 miles on the 3.0L vulkan flex fuel OHV engine. What levels of PM do you believe in or recommend? I have been thinking of doing the timming chain with guides and the water pump. I do the normal things oil & filter @ 3k, antifreeze and flushing @60k, trans fluid and filter @60k. Other than staying on top of miscellaneous repairs what do you recommend? Thanks for the advise. Excellent web site!