IMO, you should be able to safely run a smaller yoke/ujoint for the jackshaft. Its not being subjected to tcase reduction or same the angulation, abuse, etc as the other shafts.
I'd rather have more distance between the units to have say 5-10 degrees working angle on the joints. Then get the ground clearance back clocking the tcase flat.
Dodge cobbler... (1stgen cummins theme)