Which shock absorber are you using? Is it the original type with 3 lobes (in which case I can't help as I've never used one) or the later 2 lobe type with the sleeve over the cranksahft?
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.