1971 GTO Rear Axle Codes

Differential Ratio

Non Safe-T-Track Axle Code

Safe-T-Track Code

3.07*

WT

XT

3.08

WE

XE

3.23

WF

XF

3.31*

WU

XU

3.55

WH

XH

3.55*

WV

XV

3.90

N/A

XH

3.90*

N/A

XK

4.33*

N/A

XM

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