Strange timing issue - '68 318

WAIT!!! So, this is a 68 engine, and it has been rebuilt??? Are you using the early or late style front cover? Or more specifically, where is the timing mark? Between the alternator and water pump (right side) or on the drivers (left) side of the engine? If the damper was replaced during the rebuild (common practice) it was quite possibly replaced with the 1970 and later style. The marks are 90 degrees off. This might explain why the rotor is at 3 o'clock with the timing marks lined up. Hook the timing light to #3 or #2 (as opposed to the normal #1 or #6) and see if it is easier to time!