I also timed on No3. The static point of firing was when the rotor arm centre line was in line with the centre of the rubber grommet through which the two wires exit the distributor base plate. I advanced from that by Guess and by God with a bit of experience thrown in but I am not far out. To date, the Healey has always started first kick, which is what I expect from a Mk II with SU carb and electronic ignition.
I may suffer in future for that, no doubt!
My post about Steve Carter being an inspiration a day or two ago was a reference to the thought of fitting a timing disc onto the rear crankshaft using 2 (singles) nuts, using a pointer for TDC and then strobing the timing, obviously with the primary case off. Given that once you have the timing right you scribe a mark between distributor and housing so that you can set it again if need be, this might be an easy way forward.
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.