This is right. Depends on the lifters, but it's anywhere from 1/4 to 3/4 turn, depending on the rocker/threads. If you did it visually I'd say they are probably fine in terms of preload.
I remember back when I did mine that I was having a hard time getting the rocker geometry correct. BJR was coaching me through that one. The heads had been cut along with the intake of course to up the compression. Probably not the best way but installed hardened washers under the shafts to bring them up a little to fix the problem.