Did a little research on the Stempf adjustable ball joint. It is only for camber adjustment. You might be able to get a . 1 degree caster change, but that would not usually give you enough split to make a difference. I checked on the diameter of the Dana ball joint, and it is about . 003 larger diameter than the AA ball joint. Might be fun to see it it will fit in the AA knuckle. It is truly an adjustable joint.
Also, I would say mine pulls slightly right, but what I do notice is if I hold the wheel at 10 o'clock with my left hand, it goes straight, but if I hold it at 2 o'clock with my right, it drifts slightly right. Seems like it is just sensitive enough to respond to the weight of your arm. Doesn't bother me, as I hardly ever drive with my hands off the wheel. If I need both hands, I use the old knee, and it never pulls with that!