Rocker shaft cover plates; gasket sealant or not?

Add a smear of sealant to mine and it doesn't leak. As I have always done this I have no idea whether dry or simply greasing /oiling them gives the same result. 

If you assemble dry and it then leaks, then you have an oily gasket you need to seal...

Regards, George. 

Add a little more in the way of leak-proofing by putting a tiny amount of sealant on the bolt threads and remember to fit an annealed Copper washer to each of these as well..

As an old school mech engineer I nearly always apply sealant to gaskets and joint faces unless the spec says not to. My preferred sealants are the likes of Welseal or Hylomar as these are none setting types so you can remove and re-fit the cover and gasket without damaging the gasket and joint faces.

At the end of the day it's all down to personal choice.

John S

.. of Wellseal here. That's what I would use.