From your question I see you have hydraulic lifters, as most of our cars do.

 

The hydraulic lifters have a fixed travel length.  When new it requires two full turns of the rocker adjustment nut from just touching the lifter at zero lash and complete lifter compression when the piston in the lifter is bottomed out.    Zero lash is when there is no play at all, but nor is there any tension.

 

This method is not to be used with used lifters.  Used lifters need to be adjusted with the engine running as a final adjustment, but the initial adjustment can still be done this way.   Used lifters often have a slight build up inside of them which sometimes prevents this method.  When that happens the valves do not close all of the way.  More on this in a bit.

 

With new lifters in place turn the engine to top dead center on number one cylinder.  Make sure the lifters and rocker adjustment are loose and have some free play in the push rod.  If you have the intake manifold still off it's easier.   Grab the push rod gently toward the bottom, near the lifter.   Lift upward gently and you can feel the play at the bottom of the rod where it hits the lifter by slightly moving the rods side to side. 

Very slowly tighten the rocker nut while continuing to move the rod back and forth.  As the gap gets smaller, the rod will move less.  Keep in mind this takes a gentle touch.   It is very easy to use too much pressure and activate the lifter piston up and down, and throw off your adjustment.  You will be able to feel when you eliminate the play between the rod and the lifter.   Remember to be lifting upward on the rod while you make the adjustment.

 

One all the play is out of the lifter/rod/rocker adjustment turn the nut one full additional turn.  THis centers the lifter piston in the lifter, the ideal position.  Then do the next valve on number one.

 

Now you have a choice of adjusting half of the valves, the ones with the cam lobes down, then turning the engine one turn and doing the other half.   If you are not sure what is on a lobe and what is not,   Take the dist cap off and just turn the engine to the next cylinder and do those two valves.  Keep going in order until you have finished them all.   If you did it right you can put the valve covers on before you fire the car, and you won't have any oil mess.   I always do this when I have new lifters in place.

 

If the manifold is in place you can do the same thing, but it is a  much more touchy feel to get it right when you are holding the push rod near the top.

 

If the lifters are used you can do the same thing, but only tighten the nut 1/2 turn or less.  Leave the valve covers off, and start the engine.  Loosen a rocker nut and let it clatter and make noise for  several seconds.  This allows the lifter to fill with oil.   Not slowly tighten the nut until the lifter clack/click stops.  Then SLOWLY tighten the nut to one turn if it will go that far without causing a misfire.   If you do get a miss, let the engine run a bit and see if it clears up.  If not, loosen the rocker nut until the engine runs smoothly.  Now do all of the rest of the rockers/lifters one at a time.

 

There are clips you can buy that will prevent the rockers from spraying oil all over the place when you are doing the adjustments.  I highly remcommend them to prevent a mess and a stink from oil burning on the exhaust manifolds/headers.

 

But with the new cam and lifters,  just be picky and then you can button it up before you start the engine.  Much cleaner.  That also allows you to ren the engine at about 2000 RPM for several minutes to break in the cam and lifters.  Very important for a good long life.  Follow the recommendations of the cam Mfg. 

 

Just as an additional note, here is a method of installing valve covers that I use often.   Gaskets like to shift and walk out of place when using silicone sealer.  Other sealers are difficult to remove and/or get the valve covers back off of the engine if need be.   No sealer can lead to a leak sooner or later.

 

I put the gasket onto the valve cover with Hi Tack gasket sealer.  Indian head also works.   Let it set up a bit and apply silicone to the open side that contacts the heads, and put the covers on.   The silicone will seal the rough surface on the heads, and will shear and come off easy later.   The HiTack will keep the gaskets in place without walking, and can be removed fairly easily when the covers are off the engine in your hands.   It's very difficult to remove gaskets and Hi Tack from the heads when the engine is assembled.  Using this method, I have never had a comeback or a problem with the gaskets.

Mark

 

Birds of a feather.....