Pork:
I checked my end cap numbers; looking from the back (ring end facing you), with the carrier situated so the the ring is on the left:
- The cap closest to the ring or left side is marked as: 3652335 *D17
- Right side is: 3652335 *D19
Again, this is from a 1/2 ton Napco front differential, but it is the same as the rear. And I believe that is the same as a regular 1/2 ton ring & pinion set. I don't know if this helps, because my shop manual & the instructions from Patricks agree with what Dusty & others have said; the end caps are machined for a particular side. So it is possible that the part numbers are relatively meaningless. Good luck.
