ignition timing 16v

Hi guys, I recently replaced the timing belt and camshaft seals on my 16v but struggling to find the TDC mark on the flywheel, When I set the engine timing I went off the cam belt cover and checked it with the screwdriver method. Ive had the engine turning over by hand and think the timing is correct but I don't think the 6 degrees BTDC timing mark is correct? Was there one timing mark fitted to the 16v flywheels? I had a little look around and the only thing I can find that resembles mine is a diesel engine fly wheel, is this right? Thanks in advance.