Basicaly:
Main & big end bairings, Cam bairings, cam followers (Hydrolic or not??) gasket sets, oil pump, etc......
The reason I ask is beacuse of this:

Although I chainged the oil in it today to see if that would help & it did quieten down a hell of a lot, with the knock coming & going at idle..... this makes me think it's something stuck like a hydrolic tapet or something??
Cheers
Jono