If you have a 261, it had no timing mark on the timing gear cover or on one of the pulleys. There is a bb on the front face of the flywheel and a "timing window" on the front face of the distributor side of the clutch housing.
Do you have a Shop Manual for the year of your engine (1960)?
If you have a 1960 261 flywheel,
these instructions should work OK. 
