Lengths and locations have a lot to do with making it all fit where it can, no two rigs will be the same. The thing to do is to get the lowers up in the chassis where they fit and then tack in some uppers where you think you have room for them. Then run the numbers and see if they are in an exceptable ball park. I think it is more important to have a minimum amount of change through the suspension cycle rather than a specific AS number. These happen to be 50% rear and 60% front static. I also like to keep the roll center a little higher in the rear than the front, I think this helps make the rig more predictable in corners. A lot of this is pretty subjective and can very by driver though. If this is your first link job I would build some adjust-ability into the uppers at the frame at the very least and probably make sure I had room to move the brackets around, front to back, if needed. I had to screw around with my first one quite a bit to make it do what I wanted it to.
More confused now? :eeek::haha: