stock has a range though...you are dealing with mm...haven't you heard the saying that a "c unthair's width is the unit of measurement for mechanics?". We deal with precise measurements. That's how you know how far you can go. You can clay test the motor and get the real reading or take off the valve cover, advance the cam gear to say 10 degrees when the engine is off and bone cold and manually turn the crank slowly until it touches the valve... then back off 2 degrees from that reading as their hot engine limit...or guess and limit yourself to 6 degrees, some go 8 degrees.
I've actually measured how much play I have safely on my engine but I have internal work done...I have 10 degrees play. Don't guess. Stock means nothing to a person that works on an engine because stock is a range.