It's not the worst thing in the world if the egine is all cast iron,,...no aluminum heads or block. I think you may have heard "set it at the hot lash spec when cold, and then re-do it once warm" and that's meant for when you assemble an engine.
At any rate, I posted a link (above on it). Here it is again:
http://69.20.53.62/faq_mlifter.php