D35 history:
The housing, shafts and R&P are originally from CHW's XJ, which is a '88 or '89 Laredo w/ Selectrack. The differential carrier is originally from Stroker's XJ, which is a '94 or '95 Sport w/ Commandtrack. So it is a c-clip diff in a con-c-clip housing, but that still doesn't explain the difference in U-bolt sizes.