I blew a headgasket and went ahead and pulled both heads and had them checked and sent them out to be milled and get a valve job on both heads. The engine had 160K Miles, should I replace the timing chain also? I talked to a MB service manager and he said there is no recommended mileage to replace the timing chain.

Do these engines have a history of the timing chain jumping like the V8s in the W126s as they wear?