Check out
this thread . Timing marks are in reference to piston vs cam orientation. The marks indicate
piston top dead center. The ignition timing is referenced from that TDC mark. If reorient the drive and distributor, you change the physical orientation but not necessarily the
rotational orientation.
So turn the engine until the rotor is pointing at the spark plug
wire for #1, pull the distributor, reclock the drive anywhere you want (think about this ahead of time), reinstall the distributor, loosen the adjustment nut and turn the distributor until the rotor once again lines up with the #1 spark plug
wire. Rotor location/aiming vs crank rotation hasn't changed.