At what mileage does the timing chain needs replacement in Concorde 1995?

No regular service maintenance for timing chains. They don't need to be replaced unless they fail. Zee

Zee, is correct, no regular service is needed for a "timing chain", but if there is a time that you do have the chain exposed, for some other repair, and the engine has a lot of miles on it, I would go ahead and replace the chain and sprokets as an insurance against future problems. After all you are there, and chains (guides) do wear out, and a replacement kit is not really that expensive. I am a firm believer that preventitive maintence is a whole lot better than having to do an "emergency" repair.