1970 camaro 3.73 12 bolt

[gthomas]

I picked up a 12 bolt out of a 70 camaro (i believe). it has a 3.73 posi in it and the axle code appears to be c oz. Is this a z28 only rear, or available in any 70 camaro. Hope this isn't a dumb question, I am more of a mopar guy. Anyways, the story I got was that it was removed from a 70 z/28 30 years ago. Here is a pic of my 69 camaro I just sold. I love all musclecars. Can't figure out how to add images for some reason.... Figured it ou

[Dicky]

It's a '70 only, as that was the last year for 12 bolts in Camaros.

Dicky <<GRAEMLIN_URL>>/flag.gif

[jbsides]

Yup, I found out the hard way back in the late 70's with a used one. Expensive lessone, even back then.

From the NastyZ/28 web site:

Rear Axle: GM 12 bolt (only year 12 bolt used). Positraction optional. 3.73:1 ratio standard. 4.10 ratio available (RPO ZQ9).

[70 Forest Green Zee]

70 Z28 only with 4 speed

[iluv69s]

I had a few 70 SS cars back in the day with original 12 bolts also....(not only Z-28's )

please correct me if I am wrong...

[iluv69s]

..and did a 70 TA use a 12 bolt also??

[70 Forest Green Zee]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: iluv69s</div><div class="ubbcode-body">I had a few 70 SS cars back in the day with original 12 bolts also....(not only Z-28's )

please correct me if I am wrong... </div></div>

the COZ stamping is Z28 only with 4 speed. Other Camaros certainly had 12 bolt rear ends but not with a stamping of &quot;COZ&quot; that's all I'm saying

[gthomas]

Thanks for the help.

[L72Chevelle]

I have a COZ 12 bolt that I was told came out of a 70 formula firebird and had a friend that had an untouched 70 formula that also had a COZ 12 bolt in it from new.

[Lynn]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 70 Forest Green Zee</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: iluv69s</div><div class="ubbcode-body">I had a few 70 SS cars back in the day with original 12 bolts also....(not only Z-28's )

please correct me if I am wrong... </div></div>

the COZ stamping is Z28 only with 4 speed. Other Camaros certainly had 12 bolt rear ends but not with a stamping of &quot;COZ&quot; that's all I'm saying </div></div>

I am not arguing, as I don't have the knowledge base to argue this. Just asking.

If I ordered an L78, surely the 3.73:1 posi was available, correct? Not standard, but available.
Why would it be stamped with a different code as opposed to the Z/28?

[70 Forest Green Zee]

In regard to the COZ stamping...... after further investigation it appears to have been available with a Turbo 400 as well as a 4 speed in 1970 but still Z28 only. According to what I read in Chevy by the #s the 3:73 posi gear set (COZ) was only available on the 350 Z28 in 1970 and no other Camaro or any other car in the Chevy line. Here's a link to the rear end and gear info posted over at Nasty Z28, a very informative site particularly if you have a second gen Camaro

http://www.nastyz28.com/camaro/camaro70.html#axle

So Gary, in answer to your original question, the rear end that you have came out of a 1970 Z28 buy it could have been an automatic, or a 4 speed.