Timing chains do not get changed, they are designed to last the life of the motor and normally have no problem doing so.
They may stretch and wear a little bit, but they are unlikely to fail as long as the guides/tensioners stay in good health.
Timing belts have change intervals, and that is why they suck in comparison to timing chains. Seems most of the vehicles that have timing belts are the most PITA ones to work on, hahaha.