[gr868]

I have a 12 bolt out of a 67 RS/SS with the square radius rod and I need help decoding the diff gears. There's a number stamped on the outside rim of the large gear. It's 2GM 3862691 14 43 5 67. The stamp on the 12 bolt housing is Q5 05 12 G2.

Three questions: 1. What is the actual gear ratio? 2. Is it a Posi? 3. Could it be the original gears for this rearend?

Thanks for your help.

Jay
GR868

 

[vr1967]

Jay,
It is 3.07 gears. Others may correct me, but I think the 3862691 is the GM PN, 14 43 is 14 teeth on the pinion, 43 on the ring gear (43 divided by 14 = 3.07) the 5 67 should be May 1967.

 

[69crazy]

QS is factory 3.07 gears non posi .You wrote Q5 but I will guess it's QS.So it looks like you got the original gears to your rearend

 

[bertfam]

Jay it's probably "QS" and not "Q5", and that indicates a 3.07 Non-Posi 12 bolt with metallic brakes. Yours was assembled on May 12th, 1967 at the Detroit Gear and Axle plant on the 2nd shift.

Original to your car? Depends on the build date of your car. Post the VIN and the Trim Tag info and we can tell you more.

Ed

 

[gr868]

Thanks for the info, it's much appreciated.

No, it's not out of my car. But I know the car very well. It was built in June of 67.

Is the non-posi correct for an RS/SS 350?

Thanks again.

Jay
GR868

 

[bertfam]

Jay, yes the 3.07 ratio was the "economy" rear axle for the SS 350, with Posi being optional.

June built car with a May axle is perfect.

Ed