Each pair should be installed with the lifters on the base circle of the cam (valves closed). Hand tighten to zero lash first - no gap between pushrod/rocker or valve stem/rocker. From that point torque to 18-20 ft-lbs. while counting turns. It should hit the specified torque between 1/4 turn and 1 turn. If it takes more than one turn, your pushrods are too long - and you can shim the rocker up in .030" increments. If it takes less than 1/4 turn or you have trouble getting to zero lash, your pushrods are too short. The solution is longer pushrods, or removing a small amount of material evenly from the bottom of the rocker fulcrum.
Why can you only go .030 increments? How do you know it will be off by this much? And why would this guy need to shim the rockers if the heads are stock size(not milled)? Is it ok to add too much shim? Why would his pushrods be too long if nothing changed?
Saleen - I think you may be reading things into my statements that simply aren't there. The shims come in .030, .060 and .090 sizes. I mentioned the .030 size to give him an idea of the how much 'adjustment' that size makes. I didn't suggest he would need shims or longer pushrods. Note that there is an "if" in front of all those statements. I simply told him what the solutions/alternatives were depending on what he discovers when he installs them. If the heads haven't been cut, and the block hasn't been decked, and the car still has a stock HO cam, pushrods and lifters in it, then it's likely that they will all hit the specified torque within the prescribed number of turns. If any of those variables have been changed however - well, that's why they came up with this procedure for installing rockers. It will tell you if you have a dimension/geometry challenge.