1968 GTO Rear Axle Codes

Differential Ratio

Std. Axle Code

Std. Axle Sticker Code

Safe-T-Track Sticker Code

2.78

D

WC

YC

2.93

E

WD

YD

3.08

F

WE

YE

3.23

G

WF

YF

3.36

H

WG

ZG

3.55

K

WH

ZH

3.90

P

N/A

ZK

4.33

S

N/A

ZL


A sticker with code was applied to the left brake drum.
The code was also stamped in the axle housing to the left of the carrier.