If you run methanol, the closer to the valve the better with the nozzles.
If you run gas, higher up is better. I'd still keep the nozzle in the runner though and not up in the hat where some cylinders can steal from others.
If you have nozzle dribble issues that bother you or cause problems, you can use ball-check nozzle bodies and when there is no pressure, they are closed right at the nozzle.
Spud