See this page from Novaks. �If all shims are removed and still not sufficient preload, you can add a washer under top bearing cap. �Read paragraph no 5 under reassembly. � �:)
http://www.novak-adapt.com/knowledge/steering_knuckle_repair.htmThe washer would put additional pressure on the bearing and give you sufficient preload. � The addition of the washer on top of the bearing below the cap will in all likelihood result in too much preload. � You will have to then probably add some shims to back off to the proper preload.
Otherwise, if you do not wish to try the washer trick, you would probably have to try a different brand of bearings and races to see if they are thicker.