Rear axle code question

[red69]

I'm a little confused by the coding on this rearend. Maybe I'm reading the charts wrong. The casting reads C289 (March 28 69). The housing stamp reads C  BL 0120G2 (3.07 open January 20 Detroit 2nd shift) right? And why the C in front?

[bcmiller]

Does the center housing casting number end in 860 or 341?

Post all of the area by the stamping, with at least 1 inch extra on each side.

It seems that you might have a 1970 Nova rear end.

The 3 letter format for axle codes started around August of 1969. See this related thread.

http://www.camaros.org/forum/index.php?topic=10375.0

[Z10Mike]

 Casting date late March 69 and final assembly Jan 20, 1970.  That is a long time, but would indicate that Gear & Axle used whatever components were on hand to complete an axle assembly.  Probably not "normative" but the plants didn't operate on that principle.

[red69]

Casting # and larger stamping pics.

[bcmiller]

It is not common, but it looks like this was a leftover 860 casting that got used for a Nova rear end in January 1970.

The changeover from the 860 to the 341 casting took place in the Summer of 1969.  This is the first time I can remember an older casting being used for a rear end, but it has happened before on a few engines.

[red69]

Thanks for the info. That's a longtime for that casting to sit around before assembly. Nova rearend must be all the same dimensions as it bolted right in the 67 Camaro.

[bcmiller]

The 68 to 72 Nova 12 bolts ARE the same dimensions.

I found a CBS coded 70 Nova 12 bolt for my nephews 69 Camaro and another CBS for my dad's 70 Nova.