A tight valve can cause the engine to miss or run a bit rough; a loose valve is a little noisy. Don't be surprised if you hear a little noise from the valvetrain; if you adjust all the noise out, they're probably too tight.
If a valve lash is tight enough to "cause a miss" then THAT VALVE is going to be BURNED in a short time. The CAUSE of the miss is leakage past the valve seat because the valve is held open.
If you get valves "way too" loose you can hammer stuff in the valve train, IE deform the pushrod ends or rockers
the EOIC method mentioned above WORKS ON ANY poppet valve type engine.
It means rotate the engine until the EXHAUST valve just starts to move OPEN, and adjust that intake, then rotate until the INTAKE has fully opened and is "on the way" CLOSED, and then adjust that exhaust.
