Here is what I have found:
1. Typical factory settings I have always been able to dial in. This is the first car of mine with a non original height spindle. This is the 70's disc b-body spindle which was taller than the original one that it replaced
2. The factory geometry runs one way, more caster more camber. At least on this car.
3. The factory settings were not achievable. too much camber. It was close, but I didn't want the factory settings anyway, 0-3/4*positive camber and 0-1*negative caster.
4. getting negative camber along with positive caster is a tough one. Using offset bushings I was able to get 1.5 degrees positive caster but the camber was still positive. The issue is you already have the rear cam and offset bushing so that the rear of the arm is in as far as it will go. So the only way of pulling the camber back is to bring the front in from max out.Which starts to draw the caster back also.
5. shimming the lower ball joint with washers was they only last solution, reducing camber with out losing caster.
6. Unless you are pushing the max adjustment the offset bushings don't help much, mine where only required in the rear position even though I put them in both.. It allowed more inward movement of the rear of the arm beyond that of the factory cam. Because I had to wind the front in from max out to reduce positive camber it just changes the position of the cam based on the offset of the bushing, when you get to your acceptable trade off, camber for caster and vise versa.The sweet spot would have been achievable with a straight front bushing also.

My very good friend has an alignment rack in his auto repair business, but after deliberation, once the car is on the road we believe we will find the same result.