1. Right! Valve lash is the distance between the rocker and the valve in closed position.
2. You have to set the valve lash at the power stroke at every piston, when the valves are closed.
That means you start with - lets say - 1(front) and then 5,3,6,2,4. You have to rotate the crank every time.
3. Make sure what lifters and what cam you have.
The cam card tells you the lash (mostly different) for exhaust and intake. For hydraulics there is a different approach - they are set to zero lash.
Here
click is more than you ever wanted to know about valve setting and a step by step tutorial.
Have fun, Frank
