Watch this video... it explains everything you need to know about angle of the dangle.
https://www.youtube.com/watch?v=KZ-m9ov3wYM
Understand why 'angle is required'.... for the driveline u-joint cap needle bearings to operate properly they need only a minium of a 1* angle to keep them rotating. If there is no angle the needle bearings inside the caps do not turn and they will deform quicker.
When you lower vehicles there are many mods that have to take place to make everything work right as you are finding out.