[C320-list] exhaust elbow question

[Koen Bennebroek]

I seem to remember someone mentioning that the exhaust elbows on C320's get clogged and are recommended to be replaced every so often..
My local mechanic, who will do the very first service on our boat soon (so we do not have experience either with him or with the engine
service in general), recommends we order the elbow and gasket from Perkins (I believe tadiesel sells them?) in advance to save time.
 
Is this a good suggestion? We have purchased the boat used 2 seasons ago, so I have no idea what the history of this part is.
 
Thanks for any suggestions,
 
-Koen