where is this leak coming from?

[rashidme]

https://www.dropbox.com/s/s17kpk0avo4sm89/IMG_20160702_155719.jpg?dl=0

as you can see the spark plug socket is dry and so was the spark plug itself. Where is it coming from?

 

[frekeyguy]

25O OR 300? it might be from the smog plate in the valve cover

 

[rashidme]

25O OR 300? it might be from the smog plate in the valve cover

636. But why only one side? Is it bad if from valve cover?

 

[Neil_V]

Engine tilts forward in the chassis. Looks like the smog plate to me as well. 2 bolts and some silicon gasket; fixer up