tell me where i am going wrong... i have been to all the recommended web pages but can not find my axel numbers. on the axel tube i have the following stamped (passenger side inside) C BP 1204G2.

on the back of the center section (passenger side) GM 67. the driver's side has 3989340NF

67

 

That code shows to be a 1968 Year model with 2.73-1 ratio.