There are several different floats. If it's brass, set it level with the roof.
If it is the large old style brass, set the solder mark with the bottom of the sight screw hole.
If old nitophyl set level with roof, if new style nitrophyl the arms are bent differently and it's hard to say. When I ship out the new style I bend the arm so it's level with the roof at the correct level.
When in doubt, the old style "set it level with the bottom of the sight hole" kinda works, you'll want get them there and crank down the secondary bowls 1-2 flats on the adjuster.
Run 4.5psi fuel pressure ideally, but certainly no more than 6psi.
Good luck.