Possible crack in the head?

Started the dismantling process, taking the whole drivetrain out for a total check-up, and saw this patch of black. Haven´t seen it before, it´s on the right side just in front of the plug but further in, seems to be very close to the outlet valve? Feels more like soot than oil. There´s nothing like this anywhere else on the head. Wouldn´t that be just perfect, was planning to lift the head anyway, but only for a slight overhaul, grind the valves and check things over. NOT to fix a crack :evil: . But Mr Murphy and I are life-long companions, so I guess it´s the predetermined rout.... I will clean it up properly once I get the engine out and get around to build an engine stand. Any "unlucky" Norton-owners out there who recognize this?
Tommy
Please note: I did not see the previous thread when posting this, honestly, just saw it now, some coincident ha?

Looks to me like your rocker shaft end plate is weeping oil, and the stain you refer to is where that oil has been blown by the breeze. As far as I understand, that is not a common crack point.

Yes the end plate looks like it is leaking, fairly common problem. The front rocker cover could also be leaking with oil carried along the top fin. That's probably one of the hottest parts of the head by the exhaust valve, so it makes sense the oil would be "coked" by the temps there and feel sooty not necessarily oily. If compression is good and bike runs good IMHO I wouldn't worry about it unless you can acually see a crack.

Not a potential crack point. What head is it ? There are numbers stamped either above the ex. cover or nearby. Sounds like a bad head gasket allowing air to enter . If that's the case it is just labour and a new gasket and subsequent re-torque later.

Ok, thanks, so far only good feelings. The head is a RH4.
Tommy