We might now be into the ignition issues.
So, remove the distributor cap, take hold of the rotor arm with one hand and try to kick the engine over. If you can do this without the rotor arm turning, the fibre drive gear to the distributor has stripped. If it turns ok, then I need a detailed description of the coil conversion before I can offer much more help. For instance, does the lead to the coil come from the end cover of the mag? If so, is the brush in the end cover re-inforced with a spring behind it?
It may well get more detailed than this!
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.