I am in the one turn group. Especially with aftermarket lifters. That being said, and HRL and I disagree on this, but over the years I have had a few motors that you just could not get the valves adjusted using either the shop manual method or other static methods. Bleed down, weak plunger springs, air in the lifter, who really knows why. In those instances, I have to adjust them with the motor running.
I know, sounds counter intuitive, but you turn the idle down as low as possible without the motor stalling, and then the juggling begins because you have to get a wrench on the moving rocker and a screwdriver on the adjuster. I use an old vacco screw holding driver to do the adjustment and a welding glove on one hand.
Loosen the screw until it taps, turn it back in until it stops tapping, then one turn, 1/4 turn at a time for the pre load. It’s a bit of a pain but sometimes it’s the only way.
The first photo is the screw holding screwdriver I use for a running adjustment. The second is my vintage snap on valve adjuster. I use that for stock non running adjustment. Gotta love a nice vintage USA tool!
