g40 timing

[dcc]

The lower pulley on the engine I have has 2 markings, and according to Auto data, the wrong marking has been used to time up the engine, and as a result the distributor has been adjusted in order to get the engine running better. The top pulley locked into place with the timing mark in the correct place, and the bottom pulley locked into place 1 tooth out according to Autodata (very very rarely wrong). is it possible the engine had been timed up wrong?