I recently ordered a remanufactured head. This is my first time doing anything in the engine, I've done research on how to do the valve lash and what not, but this may sound stupid but when you do the valve lash does it adjust were the valves are? The head I have has them all at the same orientation, do you have to physically adjust the valves or is the only thing I need to do the valve lash? Last thing I want it my pistons slapping the valves and then I need to replace everything. Every video I've watched on YouTube the only thing they do it set the pistons to TDC and then toss the head on and only do the valve lash

 

Cylinder 1 to TDC and set mechanical timing via the timing belt. You turn the engine over by hand as you set the lash on the valves by adjusting the screw and jam nut on the rocker arm.
You will need to turn the engine over because some of the rockers will put pressure on the valves to open and close. Is that what you where asking?

 

Setting valve lash adjusts the gap between the top of the valve stem and the rocker arm that pushes it down. That is all valve lash is doing. And all you do is valve lash.

You still have to know how to set it properly.