valve adjustment

[furnitureguy-123]

O.K. Guys I am trying to adjust the valves on my 1980 300-6. Are the valves adjustable or do I just torque them down and adjust them w the pushrods? If so does anyone know the torque spec for the rocker stud nuts? Thanks for your help....

[NM5K]

It's been so long since I messed with those I forgot about the
specifics of the nuts.. Mine kept slipping loose on me after adjusting.
I eventually ended up using two nuts stacked.
One to adjust the lash, and the top one to keep the lower one from
working lose. I'm pretty sure I inverted the top nut.
But I never had any problem after doing that.
I always set the valve lash with the engine running. Zero lash is
the point where the "click" of the loose rocker becomes quiet.
Opinions vary about the best setting.. Some factory settings can
go as far as 1 full turn tighter than zero lash, but myself, I prefer
a tad looser than that. If the lash is too tight, it can lead to burnt
exhaust valves. If the factory specs said 1 full turn, I guess it would
be ok due to design. But I usually run only 1/4 to 1/2 turn past zero
lash myself. I think Ford went to basically a non adjustable design.
It's adjustable per say, but not really meant to be.. Like I say, I forgot
what the deal is.. part is the rocker stud design I think.
But I had mine eventually go loose, and finally double nutted em to
cure that once and for all, and it's fully adjustable even with the
non adjustable design.