B-I-L is finishing up replacing the head gasket on my 2000 TB (for the second time in 4 years) I know, I know. I've already heard the lecture of checking my oil and water regularly. Anyway, brought piston to top dead center according to specs , set distributor to specs, and it still won't start. Fired right up last night, then adjusted the timing and now it won't start. But which mark does he use for top dead center? There's 3 marks.