1970 GTO Rear Axle Codes

Differential Ratio

Sales Code

UPC Code

Non Safe-T-Track Axle Code

Safe-T-Track Code

3.07*

R

GX1

WT

XT

3.08

F

GU4

WE

XE

3.23

G

GU5

WF

XF

3.31*

T

GX2

WU

XU

3.55*

W

HO2

WH

XH

3.90

P

GU8

N/A

XK

3.90

-

-

WK

YK

4.33

S

GU9

N/A

XM

4.33

-

-

N/A

7N


* These ratios were offered with the optional 12 bolt rear end(455 only)
A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the left of the carrier.