BSA introduced many detailed changes to spindles and their associated parts during the short period between 1962-71, with only some of them affecting their interchangeability.  To serve the restoration process better and provide a practical answer that copes with most of these variations, Stainless Classics provides two kit types.  The most important difference is that the thread on the main spindle was either 9/16”-20 CEI (cycle) this product,  or an 11/16”-20 CEI option, covering both “fixed spindle” thread forms. Before ordering, make sure which thread you require.  If you do not have to bring together old and new threads, you are free to choose either kit type, in which case, it would be sensible to select 11/16”-20, as this seems to be the later option.  (The thread at the outer end (LHS) is always 9/16-20 CEI.) Select the type required, with or without adjusters.