replacing with new parts

When would be a good time to replace the oil pump and the timing chain? Curious as to what signs would show its time for new stuff. Before any wise cracks are made I mean before it breaks.

I usually replace the chain/gears during the freshening,but If the pump checks out good on inspection,use it. JMO of course

Excessive Play in the chain would be one sign or being replaced.

oil pump checks good, timing chain has a little play, not much. It hasn't even been used for a full season, but since I am going all out this year I will probaly just replace it for a piece of mind. Don't need any weakness for all the beat downs I have for the chevy guys.