Sorry, I think you are confused about which hex items are the adjusters and the lock nuts. The 24mm hex at the base on the head surface are NOT something you undo. The 17mm lock nut is above that, and the 14mm hex that you rotate to adjust height, are on the top of the balls that seat in the end of the rocker arms. They are just hiding under the end of the rocker arms. Take a closer look, I see them in picture 4. As far as correct lash specs, using stock specs is perfectly safe. All your sacrificing (maybe) is some performance. Just make sure you have SOME lash and you can't hurt anything.