Did GM ever make a 12 bolt rear end for the early Novas/Chevy II?

 

No. Just the ten bolt 8.5 inch.

 

I have a 12 bolt with these casting numbers
BP 5 19 G
8852980N
58 3/8” flange to flange

Trying to figure out which car this came out of

 

Could have been a Vette or an Impala. They had 12 bolt axles.

 

Chevrolet did make a 12 bolt rear end for the years 1962-1967, very rare. I inquired earlier on one site and one of the readers was puzzled as he said the casting numbers didn’t make sense and asked for more pictures which I took every picture of numbers I could find. He responded with the information that it’s off of an early Nova. Turns out it’s a 3.07 open differential. I did my own research on https://www.chevyhardcore.com/tech-s...rearend-guide/ and there it is. I measure 57.75 flange to flange and it coincides with the data listed.
Now I’m just trying to figure out what to do with it.

 

 

I posted on one of the other websites, can’t remember which one in early 2020 about this. One of the readers said he was puzzled by the numbers and researched it more and told me this was a very rare rear end as it was made for the early Novas 1962-1967. I checked on “Chevy DYI” and it states the same thing.
It measures 57.75” and supposed to be 3.07 open diff.

 

I learn something new every day.

Back then automatics were all three-speed, (not the 2-speed Powerglide). I'd want a higher gear ratio than 3.07 like a 3.42.