Crank Pulley or Distributor Mark??

P S.  I should have said I have an electronic ignition so setting the valve clearance is the objective.

You need both marks:

The mark on the distributor you need to find the right TDC (the ignition TDC).

And the mark on the pulley you need to adjust the exact position. 

The Mark on the Distributor is not soooo exact and also the position of the mark changes when you adjust the ignition. so don´t worry about that and keep your eye on the pulley.

cheers

To confirm TDC remove # 1 cylinder spark plug , insert a screwdriver into the plug hole, have a helper slowley....rotate the crank pulley by hand with a wrench  until the piston has traveled to the absolute top of the stroke. Loosen the 10mm nut on the dist clamp and with the dist cap removed, rotate the dist until the center of the rotor brass contact is aligned with the mark on the dist, this is TDC.                                          I have seen some degree pulleys mis-marked and in some cases the "stock" pulley was replaced with one that was not correct for that particular motor.

In fewer words (I know, a first for me...), the mark on the distributor body (usually around 4 o'clock, but could be a bit elsewhere) points to cylinder #1 when the rotor is pointing at it, while the mark on the crankshaft pulley aligns the piston with top dead center.  As Jan says; Keep your eye on the pulley.

(I know, a first for me...)

Must have had to pee or something :~)

Thanks guys. Much appreciated.