2000 XJ, NP231
Almost exactly 4" lift all around
Currently swapping my d35 for a 825 I got.

I am using:
-IRO hack n tap
-OEM front shaft
-RC lift Shackle brackets (1.5")

What (in degrees) should my rear pinion be?
I have various axle shims and I need an idea where I need to point my pinion

 

put the jeep on the ground and connect the driveshaft to the pinion yoke. Measure the angle of the drive shaft with an angle finder. Take the driveshaft off the pinion and put the angle finder on the flat surface of the pinion yoke and measure that angle. You want the dshaft and the pinion yoke to be within a couple degrees of parallel. Shim the axle on the spring perches to make the pinion angle 0-1 degrees below the angle of the dshaft. I like to go 1 degree under to compensate for a little acceleration roll of the axle.


This procedure worked for me and im sure there is more than one way to do this but its efficient. The other thing to check out is the condition of the front driveshaft your using for the new rear shaft. The one I was using was toast and had me chasing my tail trying to cure vibrations. Once I got a new shaft, all was good. good luck

 

You don't have to take the DS off. You can use the flat spot on the back of the dif to get that angle.

DS angle - diff angle = pinion angle which should be 1-3º.

 

when using a double cardigan drive shaft they arent parallel..