I need to adjust the rear pinion on my truck. I just swapped out a standard u-joint shaft for a CV shaft out of a 2001 4runner. My driveshaft angle right now is sitting at 18 degrees. I measured the pinion and it is pointed up 9 degrees. After the SAS with Marlin springs my truck is still sitting ass low(1.5" lower than front). I would like to use shackles to raise the truck up another inch. My rear shackle right now is 7.5". I need to know how long a shackle I would need to make up the 9 degrees and also lift it up some. I am afraid the shackle would have to be way to long. Might need to use a shim as well. any suggestions?

You'll see about 1 degree of angle change per additional inch of shackle length:
- http://www.4crawler.com/4x4/ForSale/Shackles.shtml#FAQ12

Shims are a more direct option:
- http://www.4crawler.com/4x4/ForSale/Shims.shtml

Or cut off the spring perches and relocate them to the correct angle.

would a 9.5" shackle be too long? That would lift the rear 1" and gain me 2 degrees. What size of shim would be needed to make up the rest? I know it does not change directly because you are raising the driveshaft at the same time.
Thanks

How to calculate the shim angle:
- http://www.4crawler.com/4x4/ForSale/Shims.shtml#FAQ1