Your pictures show the casting part numbers on the bottom of the diff housing. The relevant ratio numbers will be stamped into the case on the side, somewhere near the big "S". Your bolt holes are 10MM, as the e21 had 6 large holes versus the 8 smaller holes on the '02 diff. To convert use the e-21 half shafts at the diff and the '02 shafts on the wheel side. You'll need to disassemble both and create a hybrid part which will mate to both components correctly and make up the 13mm space differential. HTH