^^^LOL
Assuming you're using springs still;
Depending on soa or sua [soa= spring over axle and sua= spring under axle] You will need to weld on spring pads in the appropriate spots. It makes a big difference with the pinion centerline angle on vibration, noise.
Here is an attachment of Fords' recommendations for u-joints and driveshafts;
www.therangerstation.com/forums/attachment.php?attachmentid=12939&d=1389987591
It also depends on which activity you care about most. If you want easy cruising then follow fords recs, if racing then you may need to allow for suspension movement at full throttle to come up with the correct angles.