I don't know if it's the right way to do it but it has worked for us on our prerunner. We leveled the car side to side like mentioned above and used a dial indicator for the angle. We limited it to around 26* and haven't had a cv problem yet.
Do you typically end up with the most angle at droop or bump?
Let's say you have 18" wheel travel total, from ride height, you would want around 7" droop (40%) and 11" bump (60%). Right? or is that backwards?
im not sure how long your guys cvs will last at 26 or 27 degrees that's quite a bit you can run it at 26 degrees with zero back angle but as you and back angle to it the rule of thumb is add half a degree to every degree of back angle.
our car is strapped at 23 degrees and the shocks droop out and the axles is still 25 degrees but we have 4 degrees of back angle.
if it were my car I would keep it under 25 degrees but that's my opinion you obviously can run how ever much you feel is acceptable.
also camber change can be a good thing for cornering
you typically end up with more angle at droop. that is becouse at ride hight the axles allready have a downward angle twards the hubs.
when measuring axle angles also measure the camber. if you have 26* on your axle and 3* of negative camber than you would have 29* on your outer cv at full droop.if you have positive camber at full droop than dont add or subtract anything. if you have back angle you can jack either the front or the rear of your car up so ther is no back angle when measuring the axle angle, or you can just add 1/2* for every degree of back angle.