i have a 1992 firebird--i want to use parts off it- Rear end-i hope--needed a posi for my 88 rs build up heres the info i got off the car so far--cant find any rpo codesin console---vin number is 1g2fs23e4nl22134---stamps on rear end are j27-78 gm11 and 376450 or instead of the o maybe an 8 -can anyone help me identify these numbers please??