drive shaft angle?

So as my jeep nears completion, I am looking at all the angles. The first one is the pinion or drive shaft angles. From what I am reading (on searches here and google), the output of the transfer case needs to be parallel to the input of the differentials (pinion angle). I have a black diamond 3 inch lift which will settle over time. The front sit a little lower than the rear which I assume is due to the 283 engine and other accessories (winch, etc). When I put the lift on I assumed the pinion angles were changed as the new 3 inch springs likely rotated the differentials. I was going to use bigger front spring perches (or weld spacers) to bring the front pinion angle back to normal and use spring perch wedges in the rear.
1) is this generally a problem with only a 3 inch lift or should one not worry?
2) The actual angle between the diff/t-case is really what matters and not the angle of the drive shaft with the diff/t-case?
3) what is an acceptable angle? 3 degrees or less, or zero?
4) is there a tool to measure these angles or is it acceptable to just eye ball?
5) I can try and get pics on monday if it helps?
Thanks,
Paul

Other future angles to include caster and camber, toe in and out

 

On the 98 TJ I had, a 1.5" lift was enough to cause vibration and I had to use a Cardan driveshaft. What is important in my experience is the angle of the driveshaft, and hence the u-joints, to the differential and t-case. That is why people use shims or wedges to change the pinion angle. A tool sold by Sears and even home improvement place called an angle finder or somesuch can be used to find the angle of the parts. The flat surface of the diff cover area is perpendicular to the yoke. I'm sure you'll get replies from people with a lot more experience than me though.

Good luck,

 

5 degrees is acceptable, rear diff to drive shaft,and you can clock the rear diff to make this happen,[single ujoint] very common on lifted jeeps
you use a double carden joint [2 ujoints]on the upper end for the angle on it to be more, I do not remember the max for a double carden but it is a lot

 

Anything and everything you would want to know about driveshaft geometry: http://www.pirate4x4.com/tech/billavista/PR-shaft/index.html

It's on another forum where the language sometimes gets rough, but the article is clean and informative.