cleaned the head surface, gave it a little rub back to make sure there was nothing left of the old gasket fitment etc. I believe the head to be fine as was running 100% on a s2 turbo.
My only thought here would be that even though it was fine on another engine may not mean its automatically ok on yours.
Before you get too concerned i'd just check your simple things. Cam timing esoecially if you got no power.