Down load a manual if you have mislaid it from HERE
(Use the back and new seach buttons on the web page if necessary rather than your browser back button)
Dont forget the anodes on the drive if applicable.
We have two pencil anodes per engine, one in the heat exchanger and the other on the water pump housing - we don't have either set of engines mentioned in the post (D4s). Got all our bits from a company in watford - seemed very reasonable