I'm going to throw a curveball into the thread, and I'm curious as to the outcome.
I have done as you kids have done, tighten 1/2 to 3/4 turn max so I am at ease I didn't tighten too much, and I am tired of the valve clatter I still get.
Sometimes 1 full turn does seem too much.
Can never seem to find a happy medium so far.
According to the factory manual, and several members of our forum who worked in the factory, valves are to be adjusted with the cylinder at TDC, both valves closed.
Tighten the nut as you spin the pushrod, when it won't spin any more, tighten one turn more.
Here's the potential curveball, is that with the lifters dry, or the same if they have been run and have oil in them?
AND, since I like to smear assembly lube on the pushrod ends and rockers when I assemble an engine, will that affect the amount of nut tightening until the pushrod stops spinning as opposed to a dry pushrod and rocker ?