Valve train noise

I have checked everything. And all looks o.k. the preload on all the lifters were right on where I left them about 4 years ago. 3/4 of a turn. Some lifters were bled down because the valves were open. Thats normal. I checked the pitch of the threads on the adjusters and found that one turn is exactly 0.040". So I readjusted all lifters to one turn. How much side play should the rockers have? They do have some side play.