Finding TDC on the JT motor

[Tom Love]

Hi Guys,
I'm trying to find top dead center on my JT (4kq / Syncro) engine so I can get on with removing the cam. Bentley shows a alignment mark on the flywheel to be aligned with the opening in the clutch housing. Which opening though? There are 2. one is lower than the other. The lower one shows the teeth on the ring gear and the upper shows none.
Any help is appreciated. The darn thing is down in the garage waiting for my return.
TIA