12 Bolt ID HELP!!!!

[fouronereason]

Can anyone tell me what gear ratio these casting numbers are? On the right front of the diff has these numbers 3896839 with an N under it and on the ring gear it has 3817778 11 41 973 GM. I found this under a 74 K5 in the junk yard and I need one for mine since the repair bearing the previous owner installed won't stop leaking. Any help would be awesome, trying to go back in the morning and yank it, Thanks!!

 

[MojaveK5]

3.73 gear ratio. It's 11 pinion teeth and 41 ring teeth.

 

[fouronereason]

Thank you very much!!!!

 

[4X4HIGH]

As was already said the gear ratio is 3.73's (11 pinion teeth, 41 ring gear teeth) and the 9 73 is the month and year (September of 1973 which would make it a 1974 model).