Pushrods

Issue for me too.
Rockers with ball, should be adjusted where ball falls in line with shaft center and roller axis center for initial measurement.
Some folks just say “so many turns down”
This line should be perpendicular to the valve stem at/about mid lift. - adjusted by shaft height. Which may throw valve stem contact area off.
then measure.
Pushrods can be measured different ways. Make sure your supplier is clear on your measurement method before ordering.