1970 Mustang Transmissions can be identified by a metal tag attached to the case. The 3 speed and 4 speed transmissions were available with 2 different sets of gears.

3 Speed Transmission Tags 4 Speed Transmissions Tags RAN-AV RAT-BA RAT-BB RUG-AW RUG-AV         Close Ratio 4 speed Wide Ratio 4 speed   1st - 2.99 1st - 2.99 1st - 2.42 1st - 2.32 1st - 2.78   2nd - 1.75 2nd - 1.75 2nd - 1.61 2nd - 1.69 2nd - 1.93   3rd - 1.00 3rd - 1.00 3rd - 1.00 3rd - 1.29 3rd - 1.36   Rev - 3.17 Rev - 3.17 Rev - 2.33 4th - 1.00 4th - 1.00               Used with 200 and 250 Used with 302 2V Used with 351 2V Used with 3.25 rear ratio Used with 3.50 rear ratio   6 cyl engines.     gears and lower. gears and higher.

DATA PLATE CODE TYPE     1 3 Speed Manual 5 4 Speed Manual - Wide Ratio 6 4 Speed Manual - Close Ratio V Semi-Automatic Stick shift W C4 Automatic U C6 Automatic X FMX Automatic Z C6 (SPECIAL) Automatic