1970 Camaro rearend

[DAVE H]

My good friend just scored this 12-bolt COZ coded rear off Marketplace. Looks to be completely original with the dated 3.73 gearset and Eaton posi. Uncut spring perches and all correct measurements. His question, (that I cannot answer) was this specific to a Z-28, RS, or ?? Thanks for any information I can relay to him.
Dave

[luzl78]

z and ss

[dustinm]

I seen that.. just didnt have the time to commit

[BCreekDave]

I think just Z. SS came with a 3.55 standard and option was 4.10. Z option was 4.10 too. I've never heard of a 3.73 SS.

[FTC]

WOW,........that's a score. Most 12 bolt Chevy rear ends are prices well over a grand,...with Camaro ones being even more. And, if that was a 1st gen piece, the price goes up.

[big gear head]

RS is an appearance package and has nothing to do with performance, so that wouldn't matter. I would think that it would be Z28 or maybe L78.

[L16pilot]

As Dave mentioned, 3.73s was a Z28 only ratio for 1970, but the COZ code was also used in '70 T/As as they shared the same 12-bolt as the Camaro that year. Either way, that's a great score!

[DAVE H]

First off, a huge thank you to all who responded, much appreciated.
I'm going to take a swing at this, as my friend is a "as-is" flipper and it will be for sale. I'm looking at it first hand today. I enjoy restoration projects and reuniting rare parts with appropriate applications. I'll let ya'll know if I'm successful, he's a tough negotiator.

Dave

[soundjunky]

$250 for that is an ABSOLUTE smoking deal - the caliber of a deal that I'd wager only a select few of us might get - Congrats!

I have understood that the Camaro could have a four leaf spring, which determined different perches vs the Firebird which always used three leaf springs (and the shorter perches) - I do not know if the differential housing code changed with the different perches.

This rear was the "performance" ratio offered for the '70 Trans Am and Formula 400;
For the Firebird line this ratio was only available with a posi;
For the Trans Am a posi was standard;
For the Formula posi was a required option with this gear set;
For the both models this gear set could be ordered with the automatic (M40), wide ratio four speed (M20), close ratio (M21; was a required option; M22 not offered).

I hope some of this yammering helps someone.

[luzl78]

Originally Posted by BCreekDave

I think just Z. SS came with a 3.55 standard and option was 4.10. Z option was 4.10 too. I've never heard of a 3.73 SS.

ss l78 and 350 got the 12 bolt