So if you get #1 on tdc (#4 tappets rocking, or "on the rock")
Install the distributor so that the rotor will point to just after #1 position inside the cap (just after for advance)
If it doesn't, remove the distributor and rotate the gear/shaft until when it is installed it points to the above described position
(As this rotor spins anti-clockwise then it would be to the left of the caps #1 position)
Then as firing order is 1-2-4-3, then this is the order that the HT leads will be plugged in to the cap
working anti-clockwise from 1