When i set the lash in the car or on a engine dyno with the motor warmed up I do one side and then run the motor long enough to get the water temps back to 160 to 180 or whatever the temps where when i did the first side wrench
If I'm using a breaker bar to rotate the crank while I will watch the exhaust rocker arm and when it starts to move I will set the intake lash, I use to then rotate the crank over until the intake valve opened all the way and started to close some and then set the exhaust.
I'm going to go back to letting the intake valve close all the way and rotate the crank another 15 to 30 crankshaft degrees and then set the exhaust up

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)