I recently acquired a 2001 silverado 2wd ,ext cab , 5.3 , The Vin # is 2GCEC19T411397377 , it has only single drive wheel in the rear . I would like to see if I could have that changed out to a posi/limited slip . I believe this is a 373 gear in the rear ,10 bolt, 8.5", but not 100% sure. It is all stock. I would greatly appreciate any info that anyone could give me . I have been told it is a 30 spline (which I am not sure ) and all I would have to do is find a carrier that would bolt right in with the same specs . Please help .

Thanks