Setting Up a 2 Piece Driveshaft - HELP

[Notch1988]

Looking for ideas on what to do. I'm trying to get my pinion angle set so I can start welding the mounts, watts link and bag brackets on but I'm having issues. First, how do I get my angle of the last piece (center bearing to diff) if I haven't set my pinion angle? If I rotate my pinion up or down, it will change the angle of the driveshaft, thus then changing the angle I need to set the pinion, which then changes the driveshaft angle and it's just a vicious cycle.
Second, my angles seem pretty extreme. My first operating angle is good, sitting at 1.5 deg but my second is going to be in the teens, like 16 deg which will leave my 3rd angle fairly extreme too.
I've got the carrier bearing shimmed up 2 inches now and have no room to go more. The motor/tranny is already at 5.5 deg down.
The driveshaft is from the donor truck that I grabbed the LS motor/tranny from so it can be changed to a different setup if there's other options that would improve my angles.