I am posting this question here and also in a couple of other forums. I am in the process of replacing the head gasket on a M113.980 and I need to know what size the socket is for the CAM sprocket (E18 or E20) and I also need to know what size for the oil filter to the front cover bolt the one inside the oil filter housing is it a 40mm or what?

Also do you need to remove the CAM and rocker assembly from the head to remove it or can you get away with out doing it?

Thanks for your quick reply