1970 Camaro Rear..

[WILMASBOYL78]

I cam across a 1970 COW coded Camaro 12 bolt rear...looks to be in pretty good condition. Any ideas on value???

thanks..wilma

[marxjunk]

1100 plus depending on what there and how nice..whats COW the code for 3.31? super nice 2k

[WILMASBOYL78]

COW is a 3.55 open rear...here is a pic of the stamp.

http://www.yenko.net/ubbthreads/pics/usergals/2016/03/full-1121-40820-no4.jpg

[COPO]

Out of an SS car as Z-28 would have 3.73 or 4.10. Could it be from a '70 Nova SS?

[CamarosRus]

3:55 Open from 70 SS L-34......????

[WILMASBOYL78]

The 1970 Nova rear was the same as 68-69 Camaro. My guess this is a low horse BB rear...perhaps I will move it to the 'for sale' section and see what happens.

wilma

[Lynn]

COW is 1970 model Camaro 3.55:1 open rear.
70 Camaro is slightly wider than 67-69. 70 Nove would be the same as 69 Camaro.

[Kurt S]

Hmm, no cow jokes? Mooo!

[Jeff H]

I thought the 3.55 was standard on the L78 cars. I'm sure most had the posi though.

[iluv69s]

my orange 70Z had M-21 and 3.31 posi... I believe all original....

my silver 70Z car has original M-21 and rear coded for 3.73 posi... now 4.56's

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jeff H</div><div class="ubbcode-body">I thought the 3.55 was standard on the L78 cars. I'm sure most had the posi though. </div></div>

I think that makes sense...the 3.55 open rear would have been the 'default' unit for the L78...but, you had to order the posi-traction.

I'm working on some additional photos..more to follow.

wilma

[COPO]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">=iluv69s]my orange 70Z had M-21 and 3.31 posi... I believe all original....</div></div>


Only 3.73 and 4.10 available in 70 Z-28's. 3.31 would have been either L-48 350 or the low HP 396. 3.55 was standard in L-78 and 4.10 was optional, but believe posi traction was mandatory option on L-78's and Z-28's.

[marxjunk]

ive owned 2 real 69 Zs..both where 3.73 , neither had posi's or tachs...or cowl induction..all optional equip...and both where untouched original..

i have 4 friends with real z's..all had 3.73 non-posi...2 daytona yellow..2 hugger orange

these where all way back in the mid 80s...so..posi is optional and 3.73 is mandatory...more bread and butter z's out there than cool loaded up ones then..now..it seems all of them are loaded up...maybe options saved them..i duno..

cant comment on l-78s...never owned one....but knowing chevrolet...posi was optional in them too..but the gearing was mandatory..

just my experiences and opinions

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: COPO</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">=iluv69s]my orange 70Z had M-21 and 3.31 posi... I believe all original....</div></div>


Only 3.73 and 4.10 available in 70 Z-28's. 3.31 would have been either L-48 350 or the low HP 396. 3.55 was standard in L-78 and 4.10 was optional, but believe posi traction was mandatory option on L-78's and Z-28's. </div></div>

My first 70 L78 Nova was a non-posi 3.55 open rear. Based on window stickers I have for 70 L78 Novas...posi was an option. Not sure if this applies to Camaros but I would say it does. Perhaps others can add to this..it would be nice to see a 70 Camaro window sticker that shows the posi-traction option.

wilma

[CamarosRus]

Here's what Ive concluded after seeing Chevrolet/GM literature and contacting other
70' Camaro enthusiasts.

There was NO Camaro eng/trans combo that would have come with a 3:55 COW non posi rearend

ALL 70' L-34's came with 3:31 (Nothing Optional)

70 Z-28 was Std with 3:73 Optional 4:10 Posi was MANDATORY

70 L-78 was Std with 3:55 Optional 4:10 Posi was MANDATORY

70 L-48 4 spd Std was 3:31 Auto was 3:07

I am not listing the L-65 and 6 cyl ratios

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CamarosRus</div><div class="ubbcode-body">Here's what Ive concluded after seeing Chevrolet/GM literature and contacting other
70' Camaro enthusiasts.

There was NO Camaro eng/trans combo that would have come with a 3:55 COW non posi rearend

ALL 70' L-34's came with 3:31 (Nothing Optional)

70 Z-28 was Std with 3:73 Optional 4:10 Posi was MANDATORY

70 L-78 was Std with 3:55 Optional 4:10 Posi was MANDATORY

70 L-48 4 spd Std was 3:31 Auto was 3:07

I am not listing the L-65 and 6 cyl ratios </div></div>

OK...then how do we decide what car could have used this rear??

[MosportGreen66]

Did the '70 Camaro have a 1969 'LM1 type' option where a car got a 4bbl 350, muncie 4 speed or Th400 and a 12 bolt?

[ronzz572]

Pontiac firebird list the COW axle code. I'm thinking a pontiac firebird formula or trans am. I am not sure if it was mandatory for positraction on the 70 trans am or formula. That is the only other car line it will fit.

[CamarosRus]

Mosport, I'm not familiar with a 70' Camaro Option LM-1

I can tell you my 70' SS R/S has the Std 350/4Bbl 300 HP
Muncie M-20 12 Bolt 3:31 (Not Posi) and F-41 Suspension
Dual Exhaust.

[CamarosRus]

Scott Kiehne who owns a 70 L-78 and past owner of a 70 L-34 wrote to me ..............

&quot;As a follow up on the COW 3:55 rear axle..

Attached is a picture of the AMA spec sheet for the 1970 Firebird. It shows the Firebird Formula &amp; T/A as using a 3:55 ratio in the open &amp; posi configuration. I also found a couple of Pontiac websites that show the Firebird using COW &amp; COX codes.&quot;

[Kurt S]

Interesting, in prior years you could always order a performance or economy ratio that was one gear up or one gear down.
Doesn't appear so in 70.
Also, they limited the 3-speed manual to the L6 and the base V8.

A lot less build combinations = less plant complexity.

[Lynn]

Interesting: the chart does not include L78 combos. Added later in the model year?

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CamarosRus</div><div class="ubbcode-body">Scott Kiehne who owns a 70 L-78 and past owner of a 70 L-34 wrote to me ..............

&quot;As a follow up on the COW 3:55 rear axle..

Attached is a picture of the AMA spec sheet for the 1970 Firebird. It shows the Firebird Formula &amp; T/A as using a 3:55 ratio in the open &amp; posi configuration. I also found a couple of Pontiac websites that show the Firebird using COW &amp; COX codes.&quot; </div></div>

Are there any little special things that might indicate this was a Pontiac unit??

[marxjunk]

ive heard of the COX...its sought after and i see postings where people are searching for them

the 12 bolt in a firebird is a hard piece to get...ive seen 3 in my travels...not under restored cars..

[WILMASBOYL78]

I don't see a COW listed...and all the rears listed appear to be posi...thought the ratios aren't exactly the same from the Chevy list.

http://www.2gta.com/1970ta.html


The famed 12-bolt GM rear axle was only available in the 1970 Trans Am and was available with four popular axle ratios. The base axle ratio for all engine/transmissions except the 4-speed Ram Air IV was a 3.55:1 Teamed with the RA III, an automatic transmission, and air conditioning, a 3.08 axle was optional. When equipped with a manual transmission RAIII and air conditioning, the buyer could order up a 3.31 axle ratio. Finally, the Ram Air IV's with manuals or any other non air cars could be built with a 3.73 axle.

COT
3-Auto
3.08
RA III w/Air Cond

COV
4-Manual
3.33
RA III w/Air Cond

COX
3-Auto
3.55
RA IV

COX
4-Manual
3.55
RA III

COZ
4-Manual
3.73
RA IV - Standard

COZ
4-Manual
3.73
RA III w/o Air Cond

[Lynn]

But... the chart above doesn't list ANY THING for an L78, but there ARE some 70 L78 cars out there. I would suspect the standard rear for an L78 to be 3:55.

[WILMASBOYL78]

I don't think the L78 was even listed in any literature...maybe the salesperson's order price guide would be the only place...you had to know to 'ask for it'.

wilma

[CamarosRus]

SEE my post of Page 2...........

<span style="font-weight: bold">1970 L-78 Camaro = 3:55 POSI</span> (standard with L-78) or 4:10 POSI

[WILMASBOYL78]

Yes Chuck...I saw your post...but that still doesn't answer what the application is for this rear?????

[marxjunk]

im not sure of this..but i'll throw it out there..

on Pontiacs..71 and 72 A-bodys got 12 bolts automatically weather D-port or round...

maybe its a 71 rear...remember the strike? Im too lazy to look it up right now..

i cant remember if F-bodys where the same..but why not? Its a durability/warranty thing..just a thought..since you cant find the answer..

[WILMASBOYL78]

I'll check the casting date...good idea.

wilma

[Mr.Nickey Nova]

Chevrolet By The Numbers shows (COW) under 70 Camaros as a 3.55 and (COX) as a posi 3.55. So, I'm sure this rear was used in both the Camaro and Firebird line. Looks like starting in 71 they went with 2 digit codes.

[marxjunk]

[quote=marxjunk]
on Pontiacs..71 and 72 A-bodys got 12 bolts automatically weather D-port or round.../quote]

i was trying to say 455s got the 12 bolt automatically

[WILMASBOYL78]

Got some more info on the 12 bolt...

casting number is 3969341NF

casting date is C 8 0....March 8, 1970

wilma http://www.yenko.net/ubbthreads/pics/usergals/2016/03/full-1121-41081-img_20160319_152937440.jpg

[Mr.Nickey Nova]

Tom, check and see if any of your 70 Novas have the same cast number.

[WILMASBOYL78]

My 70 Nova L78 cars both have the same casting number as the one I listed. The center section is the same for Nova and the Camaro...difference is in the width of the complete housing...Nova is one inch shorter. 55 1/4 vs. 55 1/4...spring perch locations are also a little wider on the Camaro...and the axles are longer.

wilma

[Mr.Nickey Nova]

Thanks Tom!! My L34 has the same cast number also. I was curious if they did share the same center section.