"the better brand lifters"
"It would sure be interesting to see what the preloads were in a motor that came off the factory floor."
There are only two manufacturers of lifters, one just reopened so for a while there was only one. So I would like to know who these better brand lifters are! Comp , Crane, Lunati, all get there lifters from one of the two.
Engines from the factory come with lifters preloaded to near 1/2 travel. I set mine in center and shift at 6500+ all the time.
If you want yours set at the top you might as well just get solids. The 1/4 turn was a BS trick of the month from chevy craft or hot rod your chevy magazines years ago.
I use to set mine to the trick of the month way and got tired of clattering lifters until the engine got fully warmed up, so I started putting them in the center and problems went away and the engines run just as good or maybe better.