I know that this is not the right application for a Chevelle, but I have a friend with a 12 Bolt Rearend that I am trying to ID. The casting number is 3969341NF and the axle tube numbers are tough to make out the beginning numbers but the ending ones are ??S0111G1. There could be one or two numbers in front of the S. I have not been able to get the casting date yet. It may be for a 70 Nova. He seems to think that it is a posi but I have not spotted a D, E, or W to signify posi if I read other sights correctly.

Any Ideas?

The next step is to try to get the numbers in better condition to read and record. Then remove cover to get a peak at the carrier. This may be a stupid question, but how can I tell the differences between the different series carriers just by looking?
:confused:
Thanks!

He seems to think that it is a posi but I have not
spotted a D, E, or W to signify posi if I read other sights correctly.It may be a posi anyway... those codes will just indicate if it was "factory" assembled with a positraction unit


This may be a stupid question, but how can I tell the differences between the different series
carriers just by looking?
There are different casting numbers on the carrier (not sure which numbers correspond to with series carrier though)... easy way is to count theteeth on the gears and determine the ratio...