[Tom Goldman]

Performance Trends' 4 Link software has a very good pinion angle program. altho limited to 4 link and ladder suspensions.
it allows you to input all the relevant driveline angles and it will put it into animated motion and allow anaylisis of the changes thru the suspension travel.
Not a 100% susbstitute for on track experiments, but it does give some insite into the possible pinion angle changes a given setup will yeild.