I have an 89 camaro rallysport with the stock reaer end. How can I tell if it’s a 3 or 2 series carrier? And whats the big difference anyway? I haven’t actually crawled under it yet to get the nomenclature(hey, its cold outside) but when I do how can I tell?

 

3.08 and lower is 2 series
3.23 and higher is 3 series
What ratio do you have?
Stock, the V6 had 3.42, the V8 had 3.08's if it's a manual and 2.73's if it's an auto.
https://www.thirdgen.org/newdesign/tech/techdb.shtml