Cross Drilled or Slotted
If you're going to use a factory style shaft with a single joint at each end then you want to match the operating angles of the two joints. A cheap angle gauge will tell you at what angle the Tcase output shaft is at, what you want to do is have the same amount of angularity at the axle pinion. Point the pinion down a degree or two down from the ideal angle to compensate for springwrap when power is applied.
Basically you want both joints operating at equal but opposite angles.