When I do hydraulics, if I am going to set them down 1 1/2, I will usually go down a little bit further to make sure it doesn't stick or bottom out, then back off to the 1 1/2. You will find that as you start to turn it down, the engine will miss for a second until the lifter gets rid of the excess oil. It is a very messy procedure and you can get oil all over the place.
