Decoding a rear axle ratio-code

Hello Everyone

I’m Sonny, a new member in this forum
I’m in a long term project restoring my 4347 as I’ve own for almost 40 years now.
It’s been stored in my garage for the last 30 years.

There’s two wonderings I have at the moment, both regarding my rear axle differential.
My ratio-code is C-029 and my ‘lark is equipped with a Dual Path, running on 13’ wheels.

What does the code mean?
What’s my axle ratio actually?
Do I have a positive traction diff?

Hopefully some of you out there know the answer to my questions.
Thanks in advance
Kind regards /Sonny

c = 3.36:1

keithg wrote:c = 3.36:1

Hi Keith

Thanks a lot for your answer

I've been searching everywhere for this type of information, but haven't got any luck.
Where did you find it?

Also do you know anything about the positive traction differential?

Kind regards /Sonny

PS: Forgive me for trying to find out how to add pictures to this chat






https://i.servimg.com/u/f24/19/98/45/19/table_11.jpg

The most concise info I have found is here:
Olds Axles

I have the Buick manual as well and there is no mention of the a-b-c-codes that I have found. Also, I have been looking for a 3:08 for mine for years and have found nothing but 3:36. My car was originally ordered with a 4:10 posi, or so I am to believe. IIRC, I actually counted teeth on it when I was a kid and this is the ratio I came up with. Also never seen this ratio before or after nor in the chassis manual. The posi was eaten up years ago and the 2nd 3:36 open diff is in it now. My car was ordered as a 'drag car'. Buckets, 4sp, posi, manual steering and brakes and was shelved in the mid 60s when it was no longer competitive. My dad bought it used and kept it as a daily driver for years and I inherited it in the early 2000s.