are almost diesel strong and seldom need work unless of course they have been badly abused.

The dual row chain itself is very robust and if the engine was still in the car I would say measure stretch and if it is spot on, change plastic gtuides and runners and leave the chain alone.

Since the engine is out, I would say inspect closely and change ALL plastic guides incuding the lower one which is seldom changed since it is not failure-prone and is a pain in the ass to get to with engine-in-car. If the chain is good AND it is the factory endless chain I would leave it in there. Replacement chains use a master link and that is the weak point.

Be sure to replace the camshaft oiler fittings also.