1970 Chevelle Build Sheet

Rear Axle Codes

The rear axle identification code consists of a three letter prefix indicating the gear ratio, four digits indicating the assembly date as month/day, and a single letter suffix indicating the manufacturing location. The identification code should be stamped on the bottom or font of right axle tube either adjacent to the carrier housing or about 8" - 10" inboard from the backing plates. The particular engine RPO code is listed in parentheses as found on build sheets.

Example: CGI0629B decodes to CGI ~ 3.36:1 positraction, 0629 ~ Month [June] and Day [29], B ~ Buffalo (G=Chevrolet Gear & Axle, W=Warren, K=McKinnon Industries). If a "1" or "2" exists, it indicates the plant shift number. See bottom of page for photo examples.

Casting Numbers:
12-Bolt Casting #3969278
10-Bolt Casting #3969277

The casting numbers/letters on rear end housings may have either a prefix or suffix of "N" or "NF" and no reason has been found yet why they may have one or the other. Codes below are for Chevelle & Monte Carlo.

Prefix Axle Ratio
CCA 3.08:1 ~ 10-bolt (L14/307 & L22/250)*
CCB 3.36:1 ~ 10-bolt
CCD 3.07:1 ~ 12-bolt Positraction
CCE 3.08:1 ~ 10-bolt Positraction
CCF 3.31:1 ~ 12-bolt Positraction (L34/402)*
CCG 3.36:1 ~ 10-bolt Positraction
CCH 2.73:1 ~ 12-bolt Positraction (L48/350-4)*
CCL 2.56:1
CCM 2.56:1 ~ Positraction
CCN 2.56:1
CCO 2.56:1 ~ Positraction
CCP 2.73:1 ~ 10-bolt (L14/307)*
CCW 3.31:1 ~ 12-bolt (L34/402 & LS3/402 M.C.)*
CCX 3.07:1 ~ 12-bolt
CGA 2.56:1 ~ 10-bolt (L65/350-2)*
CGB 2.56:1 ~ 10-bolt Heavy Duty Positraction (L65/350-2)*
CGC 2.73:1 ~ Heavy Duty
CGD 2.73:1 ~ Heavy Duty Positraction
CGE 3.08:1 ~ 10-bolt Heavy Duty
CGF 3.08:1 ~ 10-bolt Heavy Duty Positraction
CGG 3.36:1 ~ 10-bolt Heavy Duty
CGI 3.36:1 ~ 10-bolt Heavy Duty Positraction
CKC 2.73:1 ~ Positraction
CKD 2.73:1 ~ 12-bolt (L48/350-4 & LS3/402)*
CKF 3.55:1 ~ 12-bolt Positraction (L78)*
CKJ 3.55:1 ~ 12-bolt (L78/402)*
CKK 4.10:1 ~ 12-bolt Positraction
CRJ 2.56:1
CRK 2.56:1 ~ 12-bolt Positraction (LS5/454)*
CRL 3.07:1 ~ 12-bolt
CRM 3.07:1 ~ 12-bolt
CRU 3.31:1 ~ 12-bolt (LS5/454)*
CRV 3.31:1 ~ 12-bolt Positraction (LS5/454 & LS6/454)*
CRW 4.10:1 ~ 12-bolt Heavy Duty (LS6/454)*
* Codes derived from build sheets. Other codes may exist.