In the Avon Manual it tells you to drill and add a splitpin to the nut that joins the cortina upright as its impossible to get any threads thru the nylock nut.
a/. Is this essential?
b/. or Can I use Loctite 501 instead?
c/. will it get thru SVA?

did not do mine and
it went throught the
sva ok

I have plenty of thread showing through the locknut so no need for a split pin.....

I had plenty of thread through locknut as well, no problem.