Setting valve lash


From: Dale Olson (Dale_Olson at dell.com)

1) Set the timing mark to 0 TDC #1.

How do you know if you are TDC #1? Well rotate the crank slightly in
both directions and see if either the intake or exhaust push rod of #1
cylinder moves. If it does you are probably TDC #6. Rotate the crank
another 360 degrees and you should be there.

2) Now you can set the following valves:
exhaust - #1, #3, #4, #8
intake - #1, #2, #5, #7

To set the proper valve lash you must set the preload of the lifter.
First you must take the slack out of the lifter, push rod & rocker arm
assembly. Do this by turning the push rod as you tight down the
rocker arm nut. As soon as you "FEEL" some resistance in the push rod
stop tighten the rocker arm nut. Now turn the rocker arm nut down 1/2
to 3/4's (max 1 full turn) of a turn in 1/4 increments. This sets the
preload.

3) Rotate the crank 360 degrees and set the other half of the valves
exhaust - #2, #5, #6, #7
intake - #3, #4, #6, #8

Method # 2

Another way to set the valves is to "set EXHAUST when the INTAKE just
starts to open then set the INTAKE when the exhaust just starts to open".
This method requires you to rotate the crank for EACH cylinder. But it
insures that the lifter is on the bottom of the cam lobe.

Method # 3

This method is very messy as you have the engine running. You will need
clips to cover the oil holes in the rocker arms or use 1/2 of an old valve
cover that has been trimmed to allow you access to the rocker adjusting
nuts.

First you set the valve adjustment so there is some preload on the lifters.
Now start the engine. Back off the rocker arm nut until you hear/feel the
rocker arm click. Now, adjust the rocker arm nut in 1/4 turn increments to
1/2 to 1 full turn.

originally from
How to set Valve Lash on Mike Donovan's web site.