[geezer#99]

Check for uniform rocker movement.
I’ve used tall pieces of cardboard as oil deflectors when running the valves.
When you set them just start with #1 and back off each nut until they click and then tighten just enough to be quiet. Do all that way. Then shut the motor off and adjust all to 1/2 turn.
Sometimes if you’re adjusting the preload too quick you can cause the motor to stumble and die.
Half a turn gets you close depending on whose lifters are in it. Factory setting is likely 1 turn but not all lifters are created the same. Some design differences from cam company to cam company.
Then do a compression check.