i need a lil help
 

will a posi unit from a 1988 camaro fit a 1983 caprice i dont kno if i got a 7.5 or 8.5 i can post pics of my caprice's differential cover if needed

post photos it always helps!

ok found out my rear is a 7.5

you will more than likely need a new ring and pinion set, as the carrier in the caprice is different from the posi unit and so you wont be able to use the gears on the old carrier...