My hall sender is underneath fyi but dizzy will work any way you like, as long as you plug sparky lead #1 in where the rotor arm points when top end is at TDC and follow the correct firing order (1 3 4 2, anti-clockwise on a 16v). As long as its close enough to run you can then set the ignition timing exactly right with a timing light.
But there isnt any reason not to fit it in the right spot while you're there, I mean you have marks and everything why not use them
If you follow everything danny said the dizzy will be in the correct position.
The cam tdc mark is on the outside of the pulley, it lines up with a mark on the rocker cover. While you're there make sure the crank also lines up, there is a notch on the crank pulley & an arrow on the cam belt cover. Remember the crank turns twice for every single rotation of the cam and dizzy, so if both marks dont line up at first try turning it over some more!
Ideally you want to use the punch mark on the flywheel as its more accurate, plus you need to be able to see the marks on the flywheel anyway to do the ignition timing. Here is a piccy, the small round dent is TDC for doing the belt timing, the large diamond is used to set the ignition timing. Mark em both with tipex so you can see em better!
