How much can you move them side to side? If they just wiggle a little its probably because the valves that belong to those rockers are probably closed so there's no pressure on them compared to the others which have pressure from the pushrods on them. I'm not 100% familiar with rockers on the 4.0L but if they have a torque spec, just torque them to that spec and if they move a little fine. I don't think you have to adjust them with feeler guages.