so I decided to replace the center carrier bearing and come to find out (after hours of searching and explaining the 35mm bearing was too small)the rear end in my '91 sedan is from a 1975 volvo xxxx has the bigger bearing and the rubber insulator type thing with the spring up top...

I'm guessing the car was rearended and for some reason a rear end 20 years older than the car itself got installed... seems to be good work... just wondering to what extent I have different parts from different years..... this 2 hour job turned into an all day marathon...

the rubber thing that's in place of the metal bracket seems old and somewhat deformed and seems to allow more play in the driveline than normal....

anyway to find out which rearend this car has?
it does have (from what I've seen)
75
Volvo
(indescernable numbers)

stamped on the lower right back corner of the differential