[westw]

I have a 10 bolt 8.5" with an axle tube code of GD G140. Can anyone tell me the gear ratio?
Thanks

 

[67 Nova Boy]

Nova codes

https://www.novaresource.org/axle.htm

It would atleast be a 1972 rear.

Dave
67 Nova boy

 

[Nova Thug]

We’ll need some more info on the vehicle it came from to help you.

Check out the Novasourse link you could probably figure it out for yourself.
https://www.novaresource.org/axle.htm

 

[westw]

https://www.novaresource.org/axle.htm

It would atleast be a 1972 rear.

Dave
67 Nova boy

We’ll need some more info on the vehicle it came from to help you.

Check out the Novasourse link you could probably figure it out for yourself.
https://www.novaresource.org/axle.htm

Thanks for the tip. :yes:
I checked at Novasource first. It is not detailed enough. The closest I can tell from research is that it came from a 1975 X Body. It is currently under a '75 Nova.

 

[westw]

This is the code on the tube.

 

[Nova Thug]

You will have to look at how the car was originally when it left the factory. If you want to know conclusively, then you’ll have to crack the cover off and see what’s in there..

Novasourse 1975 drivetrain options list.

 

[67 Nova Boy]

Is the rear from a Nova? I see a rear out of a 71/72 Monte Carlo GD=2.73

1971 & 1972 Monte Carlo Rear Axle Decoding

KD C 314 2 E

1.) Rear Axle Types:

1971 AXLE CODES & RATIOS

From the Chiltons manual:

CF 3.31 CW 3.31 GA 2.56 GB 2.56 GC 2.73 GD 2.73 GF 3.08 GG 3.36 GH 2.73 GI 3.36 GN 3.08 KD 2.73 RU 3.31 RV 3.31 RW 4.10

From the Haynes manual:

CW 3.31 GC 2.73 GD 2.73 GF 3.08 GG 3.36 GH 2.73 GI 3.31 GN 3.08 KD 2.73 RU 3.31 RV 3.31 RW 4.10

From the Chevrolet by the numbers book:

CF 3.31 CH 2.73 CW 3.31 GA 2.56 GB 2.56 GC 2.73 GD 2.73 GF 3.08 GG 3.36 GH 2.73 GI 3.36 GN 3.08 KD 2.73 RU 3.31 RV 3.31 RW 4.10

1972 AXLE CODES & RATIOS

From the Chiltons manual:

CF 3.31 CW 3.31 GF 3.08 GG 3.36 GH 2.73 GI 3.36 GN 3.08 RU 3.31 RV 3.31 RW 4.10

From the Haynes manual:

CW 3.31 GC 2.73 GD 2.73 GF 3.08 GG 3.36 GH 2.73 GI 3.31 GN 3.08 RU 3.31 RV 3.31 RW 4.10

From the Chevrolet by the numbers book:

CF 3.31 CH 2.73 CW 3.31 GC 2.73 GD 2.73 GF 3.08 GG 3.36 GH 2.73 GI 3.36 GN 3.08 KD 2.73 RU 3.31 RV 3.31

2.) Plant Codes:

B= Buick

C= Buffalo

G= Detroit Gear & Axle

K= GM of Canada

O= Oldsmobile

P= Pontaic

W= Warren MI

3.) Julian Date/Day of Year:

001-365

4.) Shift Codes:

1= 1ST Shift

2= 2ND Shift

3= 3RD Shift

5.) Positraction sources:

D= Dana Positraction Differential

E= Eaton Positraction Differential

W= Warren Motive Positraction Carrier

If your car did not have a positraction source code it does not have positraction.

 

[Custom Jim]

I'll throw this is that the older these vehicle get, the more things that can be changed.

Codes on whatever were there originally but who's to say down the road, things might have been changed or swapped out. This could have been the day after the customer got it or later on down the road.

Not to tell you your business, but do the work and the math.

Jim

 

[westw]

Thanks for the help.
I have no idea what this rear end was in originally. It may very well be the one this 75 came with. There is rust on the vin tag making it very difficult to read. I'll keep researching.

 

[loconnc]

gear ratio

Maybe the answer to your question could be as simple as calculating the ratio. I am sure there are many articles on the internet. It is easily calculated by rotating the wheels a certain number of times while observing the number of rotations of the driveshaft. Good Luck.