Go ahead and replace the chain while you are there, cheap insurance.

Also make sure to use OEM chain guides, about $3-4 each. they won't break like the cheaper $1-2 aftermarket guides and leave you with a left head valve job.

That is how I got my 380SE, customer came in and had the guides and chain replaced at another shop. they used the cheapo guides and it only lasted about a year before the exaust valves on the left side were bent.

Anyway I bought the car for a grand, did the valve job, both sides, new guides.

Rebuilt the tranny, and overhauled the famous W126 front suspension and she drives like a dream.