Was watching bad videos on youtube about adjusting valve lash. The find zero lash and tighten 1/2 turn stuff without explaining where that comes from, and why it is usually wrong for our Mopars. Most of that 1/4 to 1/2 turn adjustment is from adjusting stud mounted rockers, not shaft mounted rockers. When adjusting a stud mounted rocker arm like that, it is like a 3rd class lever. The lower the rocker ratio, the greater the adjustment has to the pushrod end. It also does not account for thread pitch of the adjuster which might be 3/8x24 tpi or 7/16 x 20 tpi (Stud mount rocker arms.) For example, a 1.5:1 rocker arm on a 20tpi stud adjuster, 1/2 turn is 0.0417" preload. With a 1.6 rocker and 24 tpi adjuster, 1/2 turn is 0.0339" preload. Not a big deal except for when suggesting using 1/4 turn. With thermal expansion the lifter could end up with zero preload. On our Mopar shaft mounted rockers, the adjuster is at the pushrod, so figuring preload is easier. 24 tpi is 0.0417" per turn of the adjuster, and 20 tpi is 0.050" per turn. On the Stud mounted adjuster, it only takes about 1/2 turn to get the same preload the shaft mounted rockers would require 3/4 to 1 turn of preload.