Re: 1970 Camaro Rear..
 

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.

Re: 1970 Camaro Rear..
 

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

Re: 1970 Camaro Rear..
 

<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??

Re: 1970 Camaro Rear..
 

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..

Re: 1970 Camaro Rear..
 

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

Re: 1970 Camaro Rear..
 

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.

Re: 1970 Camaro Rear..
 

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

Re: 1970 Camaro Rear..
 

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

Re: 1970 Camaro Rear..
 

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

Re: 1970 Camaro Rear..
 

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..