[Redrum]

I have read comments several times that seem to indicate that there are not 4:11 gears for 12 bolt housings. I would like to know a bit more about this topic as I counted the teeth on my gear set and it was 37/9 or 4:11's???

So, what is the scoop from those that may know?

 

[shaddow]

I have a set of Auburn 4:11s in my 12 bolt housing. . . . .

 

[Junkyard Dawg]

They make 4.10's too.

 

[Bow_Tied]

Not totally sure on this, but I believe the original GM gears were 4.10:1 (41/10) and after market gears are as you have, 4.11:1 (37/9) - Anyone confirm?

 

[Doug Garland]

Look on the housing, and see if you can find a code. My guess is ...it is KQ, as I have an idea about your car. Anyway, the M-22, which was in you car, was a heavy duty option, and the rear probably was the same. The racing angle probably was the reason for the M-22, and thus my guess about the rear coding probably is correct. If it isn't that code, look for a KK code. It is 4.10 posi also.

For all who are interested, KQ was a 4.10 Posi, H/D rear installed in C.O.P.O cars. I think his car probably was one in the beginning, but is missing the engine, and tranny. The car had a interesting history, racing up in the north west from what I recall you saying.
The count is 9-37, as you stated above.

So, how you been lately? Got that car finished yet? Doug

 

[big gear head]

I think the factory gears were 4.11 and most after market gears are 4.10. The 4.11 has 37 teeth on the ring gear and 9 on the pinion. The 4.10 has 41 teeth on the ring gear and 10 on the pinion.

 

[Redrum]

Doug,

Follow the links in my signature to the current version of my ride. I will have to go check the codes on the rear housing and post them especially if it is a KQ! That would get Bain drooling if he finds this thread... hehehehe :waving:

Yes it has history. It was campainged up in the Northwest as "Rat Magic". I still have not found anything more on it's history though. I know this to be factual as I found the "Rat Magic" under the black paint on the car and above the stock paint on the doors.

 

[Cameano]

I have a Camaro BX coded rear lying around. Too bad it sat outside for so long. The date code is unreadable, rusted away, basically. From what I've learned, if it were from a '68, it would be a factory option. '69, however, would most likely be COPO, but it could've been special ordered. 4.88 posi. Definitely was in something fast.

 

[Bow_Tied]

I think the factory gears were 4.11 and most after market gears are 4.10.

Perhaps I do have it backward, I was referring to this chart which may be inaccurate, dunno?

http://www.chevelles.com/years/69/69rearcodes.html

 

[Doug Garland]

I'm with you Ron, The Colvin book has the 37-9 coded as a 4.10 ratio, both KK, and KQ.

Car looks good Mike. Which ever code it has under it, it was still probably a special order car, with racing in mind.