You don't need to find TDC to set valve clearance. In fact, you'll do a better job of setting the valves if you don't.
Exhaust Opening, Intake Closing Method.
Rotate the engine in the direction it runs until the exhaust valve just starts opening. Set the intake valve lash.
Rotate the engine in the direction it runs until the intake valve is nearly finished closing. Set the exhaust valve lash.
You will be setting the clearance with the cam follower on the base circle of the cam, directly opposite the peak lift portion of the cam lobe. No other method does this.
Exhaust Opening, Intake Closing. E O I C That's all you have to remember.