1970 Mustang Axles can be identified by a metal tag attached to the case.
(TLok = Traction Lok Limited Slip Differential)
 
Axle Types
TAG Ratio Ring Gear Type TAG Ratio Ring Gear Type
               
WCZ-F1 3.00:1 8 Open - 2 pinion WES-AJ 3.25:1 9 Open - 4 Pinion
WCZ-V 2.79:1 8 Open - 2 pinion WFB-C 3.25:1 9 TLok - 4 Pinion
WDW-F 3.00:1 8 Open - 2 pinion WFB-D 3.00:1 9 TLok - 4 Pinion
WDW-J 2.79:1 8 Open - 2 pinion WFD-A 3.50:1 9 TLok - 4 Pinion
WES-F 3.00:1 9 Open - 4 pinion WFD-B 3.91:1 9 TLok - 4 Pinion
WES-M 3.25:1 9 Open - 4 Pinion WFD-C 4.30:1 9 TLok - 4 Pinion
WES-T1 2.75:1 9 Open - 2 pinion WFD-D 3.91:1 9 TLok - 4 Pinion
WES-AA 3.00:1 9 Open - 2 pinion WFD-E 4.30:1 9 TLok - 4 Pinion
WES-AB 3.25:1 9 Open - 2 pinion WFD-F 3.50:1 9 TLok - 4 Pinion
WES-AC 3.00:1 9 Open - 4 pinion WFD-L 3.00:1 9 TLok - 4 Pinion
WES-AD 3.25:1 9 Open - 4 pinion WFL-A 3.00:1 8 TLok - 2 Pinion
WES-AE 3.50:1 9 Open - 4 pinion WFS-A 3.00:1 8 TLok - 2 Pinion
WES-AH 3.00:1 9 Open - 4 pinion        
 
REAR AXLE CODES
OPEN TLok Ratio
0   2.50:1
2 K 2.75:1
3   2.79:1
4 M 2.80:1
5   2.83:1
6 O 3.00:1
7   3.10:1
8   3.20:1
9 R 3.25:1
A S 3.50:1
B   3.07:1
C   3.08:1
F X 2.33:1
  V 3.91:1
  W 4.30:1