C3 Corvette Rear Axle Ratios & Identification Codes

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1968 Corvette Axle Ratios

Code Ratio Application
AK 3.36 Standard (327/350)
AL 3.08 Positraction (327/350)
AM 3.36 Positraction (327/350)
AN 3.55 Positraction (327/350)
AO 3.70 Positraction (327/350)
AP 4.11 Positraction (327/350)
AS 3.70 Standard (327/350)
AT 3.08 Heavy Duty Positraction (427)
AU 3.36 Heavy Duty Positraction (427)
AV 3.08 Positraction (427)
AW 3.08 Heavy Duty Positraction (427)
AY 2.73 Heavy Duty Positraction (427 Turbo-Hydra-Matic)
AZ 3.55 Heavy Duty Positraction (427)
FA 3.70 Heavy Duty Positraction (427)
FB 4.11 Heavy Duty Positraction (427)
FC 4.56 Heavy Duty Positraction (427)

Note: 1968 C3 Differentials were manufactured at Warren and are suffixed 'W'. 

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1969 Corvette Axle Ratios

Code Ratio Application
AK 3.36 Standard (327/350)
AL 3.08 Positraction (327/350)
AM 3.36 Positraction (327/350)
AN 3.55 Positraction (327/350)
AO 3.70 Positraction (327/350)
AP 4.11 Positraction (327/350)
AS 3.70 Standard (327/350)
AT 3.08 Heavy Duty Positraction (427)
AU 3.36 Heavy Duty Positraction (427)
AV 3.08 Positraction (427)
AW 3.08 Heavy Duty Positraction (427)
AY 2.73 Heavy Duty Positraction (427 Turbo-Hydra-Matic)
AZ 3.55 Heavy Duty Positraction (427)
FA 3.70 Heavy Duty Positraction (427)
FB 4.11 Heavy Duty Positraction (427)
FC 4.56 Heavy Duty Positraction (427)

 

Note: Most 1969 C3 Differentials were manufactured at Warren and are suffixed 'W'.

1969 models built after approximately August of 1969 use 1970 coded differentials. 

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1970 Corvette (Late 1969) Axle Ratios

Code Ratio Application
CAK 3.36 Standard (350)
CAL 3.08 Standard (350)
CAM 3.36 Positraction (350)
CAN 3.55 Standard(350)
CAO 3.70 Positraction (350)
CAP 4.11 Standard (350)
CAS 3.70 Standard (350)
CAT 3.08 Heavy Duty Positraction (454)
CAU 3.36 Heavy Duty Positraction (454)
CAV 3.08 Standard (454)
CAW 3.08 Standard (454)
CAX 3.36 Heavy Duty Positraction (454)
CAY 2.73 Positraction (454 Turbo-Hydra-Matic)
CAZ 3.55 Heavy Duty Positraction (454)
CFA 3.70 Positraction (454)
CFB 4.11 Heavy Duty Positraction (454)
CFC 4.56 Heavy Duty Positraction (454)
CLR 3.36 Standard (454)

 

Note: Positraction became standard equipment in 1970 and the reference of Standard axle codes is in conflict.

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1971 Corvette Axle Ratios

Code Ratio
AA 3.55
AB 3.70
AC 4.11
AD 4.56
AW 3.08
AX 3.36
LR 3.36

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1972 Corvette Axle Ratios

Code Ratio
AA 3.55
AB 3.70
AC 4.11
AW 3.08
AX 3.36
LR 3.36

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1973 Corvette Axle Ratios

Code Ratio
AA 3.55
AB 3.70
AC 4.11
AW 3.08
AX 3.36
LR 3.36

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1974 Corvette Axle Ratios

Code Ratio
AA 3.55
AB 3.70
AC 4.11
AW 3.08
AX 3.36
LR 3.36

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1975 Corvette Axle Ratios

Code Ratio
AA 3.55
AB 3.70
AC 4.11
AY 2.73
AW 3.08
AX 3.36
LR 3.36

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1976 Corvette Axle Ratios

Code Ratio
OA 3.08
OD 3.36
LR 3.36
OB 3.55
OC 3.70

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1977 Corvette Axle Ratios

Code Ratio
OA 3.08
OD 3.36
LR 3.36
OB 3.55
OC 3.70

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1978 Corvette Axle Ratios

Code Ratio
OK 3.08
OM 3.36
OH 3.55
OJ 3.70

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1979 Corvette Axle Ratios

Code Ratio
OM 3.36
OH 3.55
OJ 3.70

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1980 Corvette Axle Ratios

Code Ratio
OF 3.07
OH 3.07

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1981 Corvette Axle Ratios

Code Ratio Application
OJ 2.87 Automatic Transmission
OK 2.72 Manual Transmission

 

1968 1969 1970 1971

1972

1973 1974 1975 1976 1977 1978 1979 1980 1981 1982

1982 Corvette Axle Ratios

Code Ratio Application
OA 2.72 Standard Wheels
OF 2.87 Aluminum Wheels