I use the race method to set up the lash or preload on all my motors, it is using a remote starter button very easy to do and remember after doing it a couple of times
You can do it cold or hot, it works either way the same. I start by reducing the lash by .006 cold on a iron block with aluminum heads by removing the valve cover and using the remote starter button I bump the motor over until the front exhaust valves just start to open, I then set the lash on the intake valve, then bump the motor over a little bit at a time until the intake valve opens all the way and starts to close a little bit. I set the exhaust lash then and go to the next cylinder in line and repeat both steps until the last cylinder is done on that side
Once both sides are done I will go drive the car for 15 to 20 minutes to get it up to operating temperature and get the oil hot, I'll reset them again with the motor warmed up to find out how much the lash has increased or decreased with the warm motor. Same deal, one side at a time front to rear and rerun it before doing the other side to get it back to operating temps. before doing the other side
Don't be surprised on the changes hot to cold, not all motors respond exactly the same
One of my street motors with Edlbrock heads only change .001, another street motor with the same part number RPM heads changed .008
Have fun, write down the changes for future use