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[C2] 66 Differential Code AN

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Old Dec 29, 2018 | 10:14 AM
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Default 66 Differential Code AM

Here are the codes for 1966.
Can someone explain to me the difference in the "AM" "Manual Transmission" description as the other ratios have 4-Speed notations.


CodeRatioTypeAK3.36:1Standard Manual Transmission or Powerglide (327)
AL 3.08:1Positraction 4-Speed (327)
AM 3.36:1Positraction Manual Transmission (327)
AN 3.55:1Positraction 4-Speed (327)
AO 3.70:1Positraction 4-Speed (327)
AP 4.11:1Positraction 4-Speed (327)
AQ 4.56:1Positraction 4-Speed (327)
*
AR 3.08:1Standard Wide-Ratio 4-Speed (327)
*
AS 3.70:1Standard Close-Ratio 4-Speed (327)
AT 3.08:1Positraction 4-Speed (396/427)
AU 3.36:1Positraction 4-Speed (396/427)
AZ 3.55:1Positraction 4-Speed (396/427)
FA 3.70:1Positraction 4-Speed (396/427)
FB 4.11:1Positraction 4-Speed (396/427)
FC 4.56:1Positraction 4-Speed (396/427)
Note: All 1965-67 Corvette rear axles were manufactured at Warren and are suffixed “W”. Listed 1967 “AQ” and “AR” codes & ratios may only have been used early in the 1967 model-year, or not at all.

Last edited by SoCalErv; Dec 30, 2018 at 05:59 PM. Reason: Correction
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Old Dec 29, 2018 | 10:26 AM
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I am no expert but could mean the 3 speed transmission. Brighter minds I am sure will correct me if I am wrong.
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Old Dec 29, 2018 | 11:57 AM
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Originally Posted by smacota1
I am no expert but could mean the 3 speed transmission. Brighter minds I am sure will correct me if I am wrong.
You are (almost) correct. It the specific case of "AM" it is a posi-traction rear axle approved/available for both the 3 speed and 4 speed transmissions for the small block engine



Larry

EDIT: If only 4-speed is shown, 3 speed and auto trans cars could not obtain it as a factory approved option. But $$$$ also talks, and perhaps a special order could be done. Maybe.

Last edited by Powershift; Dec 29, 2018 at 12:06 PM.
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