COPO 9511

[PeteLeathersac]

Cool bulletin and thanks for posting it Marlin!.
Being a '69 w/ 4:10 I suppose it's not a 9511 car, unless 4:56/4:88 gears were swapped down to the 4:10's?.

Is this bulletin car the GR #393985 Stauffer car on the list/pictured below?.
Was the '69 Yenko Nova 'EC fiasco' car a red one and this same Vin or another?.

Someone needs to update this below linked page to include Copo 9511..
Charley/Mods?.
https://www.yenko.net/dealers/copos.htm


[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete


Bulletin/Stauffer car?.

[YENKO DEUCE REGISTRY]

Yes, the bulletin car and the picture are one &amp; the same. Note the separate '427' emblem on the fender vs. some that had the integreated version (ala Impala).

Sorry, I thought the discussion was around whether a '69 Nova could come with a gear ratio higher than 3.55 without it being a copo. I'm a little late to the party, but I always thought that the 9511 was for the special gear in the 'vairs. Maybe not, my memory is going....

[Schonyenko2]

While Pete is talking about 9511 COPO for 4.56, and 4.88 availability, there's a 2nd sub discussion going on about rear ratio availability in 69 Novas. They are connected, but I suppose are two different discussions.
The 1st discussion about the 4.56-4.88 rears lead to the 2nd when I had some people acert that 3.55 was the highest ratio (BT) and 4.10 was a dealer installed option. I can't refute that acertion with any paperwork, or documentation, nor at this time can Greg Roberts.
So we actually have two discussions going on here that really are pretty inportant, and could change the way we look at some Novas. The Yenko 69s are one big important example. We assumed they had BV 4.10 rears, but now are wondering if they were BTs that Don changed to 4.10. We would hope to find some answers here. So, please try to find some documentable evidence to show how this all was done. If we need to move the thread again to a more heavily trafficed area., that's fine, as I'd sure like to get as much input as possible.
Or if the mods would like to split the subject, that's fine, but at some level I tend to think they may be related.
Schonye

[PeteLeathersac]

For whatever reasons the Non Copo 3:55/4:10 and other factory and dealer supplied axles were included in this Copo 9511 discussion at the beginning and I've been trying to nicely bump it into the true 4:56/4:88 only facts all along..
So yes please let's separate the two subjects!.

Here's a link below to a new Copo 9511 thread and more specifically to <span style="text-decoration: underline">1969</span> when Copo 9511 included factory installed 4:56 &amp; 4:88 only ratios..
1969 Copo 9511 A/F/X Body cars also 'Vettes were built and although largely unrecognized are true performance option '69 Copo cars to look for...especially the built but not found yet real '69 Copo Novas!.

https://www.yenko.net/ubbthreads/ubbt...575#Post457575


[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete

[JoeC]

Yenko used a COPO 9513 for the Stinger Corvair project 3:89 positraction differential

some info may be found by researching the speedo cable adaptors that were needed for the 4:10 rear.

I am not sure if they were needed for 4:56 or 4:88 or if they had anything to do with the RPO G84 that was added to the window sticker for 4:10 gear. It was only $2.15.

Looking at 1969 window stickers a 3:73 gear car only has RPO G80 but a 4:10 gear car has RPO G80 and RPO G84


Maybe the COPO 9511 needed a special speedo cable adaptor?

[Pat70Z]

Looks like it's been a while since anyone posted on this thread, but I have questions.
In going over my recently purchased 1970 Z28 I found I do not have a COZ or COO coded differential. Sometime in the last 54 years the differential was swapped. It has also been re-geared to 3.55. What I have is something that may be of interest to the folks on this forum.

Differential tube stamp: BW 0429 G2
- 4.56 12 Bolt April 29 Second shift, Detroit Axle Plant

Casting Number: 3894860 NF
- 1967 - 69 Camaro (also 68-70 Nova)

Casting Date: D 189
- April 18, 1969

wheel mount to wheel mount: 60.00 inches = 1967-69 Camaro

Research says the 4.56 was not available as a standard option in 1969 and was only available with a COPO 9511 option.

The '69 housing is 2.5 inches narrower than the 1970 Gen 2 version. I will be searching for a correctly coded COZ housing for my 1970 Z. If someone has need of a 1969 BW coded differential housing, let me know.

[DAVE H]

P.M. sent.

[big gear head]

Originally Posted by Pat70Z

Looks like it's been a while since anyone posted on this thread, but I have questions.
In going over my recently purchased 1970 Z28 I found I do not have a COZ or COO coded differential. Sometime in the last 54 years the differential was swapped. It has also been re-geared to 3.55. What I have is something that may be of interest to the folks on this forum.

Differential tube stamp: BW 0429 G2
- 4.56 12 Bolt April 29 Second shift, Detroit Axle Plant

Casting Number: 3894860 NF
- 1967 - 69 Camaro (also 68-70 Nova)

Casting Date: D 189
- April 18, 1969

wheel mount to wheel mount: 60.00 inches = 1967-69 Camaro

Research says the 4.56 was not available as a standard option in 1969 and was only available with a COPO 9511 option.

The '69 housing is 2.5 inches narrower than the 1970 Gen 2 version. I will be searching for a correctly coded COZ housing for my 1970 Z. If someone has need of a 1969 BW coded differential housing, let me know.

The '70 ('70-'81 61 inches) rear end is exactly 1 inch wider than the '69 ('67-'69 60 inches) rear end. There is a lot of completely wrong information about rear end widths on the internet. The spring perches on the '70 rear end are 2 1/4 inches farther apart than the '69, so if someone put a '69 rear end in your '70 then they had to move the spring perches.

[Pat70Z]

Looks like Freddie is probably correct. I measured the spring perches center to center and they are 45 3/8 - the correct distance for a 1970 Camaro. But the numbers on the tube and the housing don't lie; they are from a 69 Camaro. It is not hard to imagine that sometime in the last 54 years someone swapped the axle into my car and re-located the spring perches. There is a lot of years of paint and such on the differential, but I imagine if I got into it I would find the original perch locations.