Hi I have a 62 Special with a v6 that has a rear differential marked with the following A-121 . I just bought a crashed 4 door with the 215 V8 . That rear diff has the following ( I think ) code A-296 . How do I interpret what these codes mean . The Buick service manual does not give any indication how to read these codes, just where they are on the diff . It does talk about different gear ratios from the standpoint of selecting different speedo gears to keep it accurate if you change the diff. Anyone know how to interpret these codes Thanks Justin
