Thanks for the response. The front driveshaft looks like it is already "pushed" into the transmission, but it looks like its pretty stationary with the carrier bearing holding it in place. The back driveshaft has 2" or so of spline remaining. This looks like where all the action is (length adjustments during driving).
I took it to a spring shop (really neat old school folks
http://sacramentospring.com/). They aren't even sure I can make up the pinion angle difference with spacers. The perches may have to be relocated, which kinda ticks me off as I just had the rear end rebuilt from lug nut to lug nut, including perches (ring and pinion, axels, bearings, tube alignment, etc.). They will re-install the lowering springs for me (as I can’t drive it there if I put them on at home) and check it all out to see what needs to be done to make everything work. $$$