[fixit-p]

It really depends on what your angles are. In the diagram below lets assume that the transmission is sitting down 4* and we want a 1- 1.5* operating angle on u-joint #1 we can set drive-line #1 down either 3-3.5* or 5-5.5* that gives you some flexibility. Lets say we go with 3* down, now in relation to the transmission drive-line #1 is going uphill but thats OK because u-joint #1 now has a 1* operating angle (4*-3*=1*). The rear ends pinion angle needs to be set at 3* up so that its centerline is parallel with drive-line #1's centerline this makes the operating angles of u-joints #2 and 3 equal, this is what will cancel out vibration. To calculate the operating angles of u-joints 2 and 3 subtract the angle from drive-line #1 from the angle of drive-line #2. I hope that makes sense.