I've just sent the following query to AN, but pending their reply, I'd be interested to hear what others think.
"According to the factory parts book the five bolts securing the crankcase to the front Isolastic mounting and gearbox cradle take washers under the nuts but not under the bolt heads (and your engine fixing set 13.1663 follows this).
"While I am only an amateur mechanic this does not seem like good practice (and the PO of my machine has fitted washers at each end). I would be interested to hear any comment you have on this."
Not sure what happened, the 68-70 kit and the MK3 kit is correct. 70-74 Kit will be corrected shortly.
Point to note is that the parts diagrams and the listed description and quantities do vary, the typical example and the resulting cracked oil tanks are evidence. Use two washers for the lower mounting, the picture shows one but the listed items says two. A washer goes either side of the grommet insert.
As Ashley says, one should always check the list for quantities.
The diagrams evidently assume a certain degree of general knowledge/common sense.
An implication is that one should similarly apply these qualities if using the diagrams as guides to assembly …