2.4 dohc maintance questions

i have a 96' cav with a 2.4. I'm coming close to 100k miles. i did all normal maintanance (coolant flush, tranny fluid and filter change, ec.) i've heard alot of stories about problems with timing chains and heads blowing when they reach around 100k miles. anybody know of any extra maintance steps i can do to help prevent any serious problems? i also notice that it hesitates and the idle loops for the first 2-3 miles when i start it up, any ideas? thanks