Differential oil blowing out

Looks like a triangulated 4-link, maybe they moved the vent for one of the top brackets. I have the same, but didn't have to move the vent. My '72 would puke oil out all the time, while waiting for a replacement, I used a brake line and bent a pig tail into it, leak stopped. I never have put the new vent in.
I did not move the vent, that's where it was when I put the rear end in. I put the RMS suspension in. Is a mystery.