As the engine and it parts heat up, clearances change. You can add .003 to the spec and set them cold if you want but...
You're cheating yourself out of the experience of riding the running rockers with a feeler gauge in one hand and a boxed end wrench in the other. About the time you've got the rhythm / hang of it and actually enjoying it, you have ran out of rockers to adjust.
I group this experience with jail and ***** house. Gotta do it once just so you can say "been there done that".
