1964 and later A Body and 1965 Big Car Axle ID codes are stamped here
1965-1967 Nodular iron cases are stamped with a large “N” as shown
1964 and earlier Big Car carriers are stamped as shown with axle and anti-spin indicators.
Oldsmobile Differential Codes 1964-1967
| Oldsmobile Differential Codes 1964-1967 | |||||
| Year | Model | Rear Ratio | Tooth Count | Std Code | Posl Code |
| 1964 | Cutlass-442 | 2.78:1 | 39/14 | C | Tagged |
| 1964 | Cutlass-442 | 3.08:1 | 40/13 | A | Tagged |
| 1964 | Cutlass-442 | 3.23:1 | 42/13 | B | Tagged |
| 1964 | Cutlass-442 | 3.36:1 | 37/01 | E | Tagged |
| 1964 | Cutlass-442 | 3.55:1 | 39/11 | D | Tagged |
| 1964 | Cutlass-442 | 3.90:1 | 39/10 | F | Tagged |
| 1964 | Big Car | 2.56:1 | 41/16 | 3 | L |
| 1964 | Big Car | 2.69:1 | 43/16 | 2 | L |
| 1964 | Big Car | 2.87:1 | 43/15 | 7 | L |
| 1964 | Big Car | 3.08:1 | 40/13 | 0 | L |
| 1964 | Big Car | 3.23:1 | 42/13 | 9 | L |
| 1964 | Big Car | 3.42:1 | 41/12 | 8 | L |
| 1964 | Big Car | 3.64:1 | 40/11 | 6 | L |
| 1964 | Big Car | 3.90:1 | 39/10 | 4 | L |
| 1965 | Cutlass-442 | 2.78:1 | 39/14 | SA | SB |
| 1965 | Cutlass-442 | 3.08:1 | 40/13 | SC | SD |
| 1965 | Cutlass-442 | 3.23:1 | 42/13 | SE | SF |
| 1965 | Cutlass-442 | 3.55:1 | 39/11 | SI | SJ |
| 1965 | Cutlass-442 | 3.90:1 | 39/10 | Dealer Installed | |
| 1965 | Cutlass-442 | 4.11:1 | 37/09 | Dealer Installed | |
| 1965 | Big Car J-88 & 88 | 2.73:1 | 41/15 | QA | QB |
| 1965 | Big Car J-88 & 88 | 2.93:1 | 41/14 | QC | QD |
| 1965 | Big Car J-88 & 88 | 3.08:1 | 40/13 | QE | QF |
| 1965 | Big Car J-88 & 88 | 3.23:1 | 42/13 | QG | QH |
| 1965 | Big Car J-88 & 88 | 3.42:1 | 41/12 | QI | QJ |
| 1965 | Big Car 98 | 2.73:1 | 41/15 | QK | QL |
| 1965 | Big Car 98 | 3.08:1 | 40/13 | QM | QN |
| 1965 | Big Car 98 | 3.23:1 | 42/13 | QO | QP |
| 1965 | Big Car 98 | 3.42:1 | 41/12 | QR | |
| 1966 | Cutlass-442 | 2.78:1 | 39/14 | SA-SK | SB-SL |
| 1966 | Cutlass-442 | 3.08:1 | 40/13 | SC-SQ | SD-SR |
| 1966 | Cutlass-442 | 3.23:1 | 42/13 | SE-SV | SF-SW |
| 1966 | Cutlass-442 | 3.55:1 | 39/11 | SI-SX | SJ-SZ |
| 1966 | Cutlass-442 | 3.90:1 | 39/10 | TG-TJ | TH-TK* |
| 1966 | Cutlass-442 | 4.33:1 | 39/09 | Dealer Installed *Pontiac | |
| 1966 | Big Car J-88 | 2.78:1 | 41/15 | RA-QV | RB-QU |
| 1966 | Big Car J-88 | 3.08:1 | 40/13 | RC-RI | RD-RJ |
| 1966 | Big Car J-88 | 3.23:1 | 42/13 | RE-RK | RF-RL |
| 1966 | Big Car 88 | 2.73:1 | 41/15 | QA | QB |
| 1966 | Big Car 88 | 2.93:1 | 40/13 | QC | QD |
| 1966 | Big Car 88 | 3.08:1 | 42/13 | QE | QF |
| 1966 | Big Car 88 | 3.23:1 | 41/12 | QG | QH |
| 1966 | Big Car 88 | 3.42:1 | 41/12 | QI | QJ |
| 1966 | Big Car 98 | 2.73:1 | 41/15 | QK | QL |
| 1966 | Big Car 98 | 3.08:1 | 40/13 | QM | QN |
| 1966 | Big Car 98 | 3.23:1 | 42/13 | QO | QP |
| 1966 | Big Car 98 | 3.42:1 | 41/12 | QR | |
| 1966 | Toronado | 3.23:1 | QO-QP | - - | |
| 1967 | Cutlass-442 | 2.41:1 | 41/17 | SS-SU-ST | TA-TS-TB |
| 1967 | Cutlass-442 | 2.78:1 | 39/14 | SA-S2-SK | SB-S3-SL |
| 1967 | Cutlass-442 | 3.08:1 | 40/13 | SC-S4-SQ | SD-S5-SR |
| 1967 | Cutlass-442 | 3.23:1 | 42/13 | SE-S6-SE | SF-S7-SW |
| 1967 | Cutlass-442 | 3.55:1 | 39/11 | TL-S8-TP | TM-S9-TQ |
| 1967 | Cutlass-442 | 3.91:1 | 43/11 | TN-T2-TU | TO-T3-TV |
| 1967 | Cutlass-442 | 3.90:1 | 39/10 | - - | TH (W-30) Pontiac 4 Pinion |
| 1967 | Cutlass-442 | 4.33:1 | 39/09 | - - | Dealer (W-30) Pontiac 4 Pinion |
| 1967 | Big Car J-88 | 2.78:1 | 39/14 | RA-QV | RB-QU |
| 1967 | Big Car J-88 | 3.08:1 | 40/13 | RC-RI | RD-RJ |
| 1967 | Big Car J-88 | 3.23:1 | 42/13 | RE-RK | RF-RL |
| 1967 | Big Car 88 | 2.73:1 | 41/15 | QA | QB |
| 1967 | Big Car 88 | 2.93:1 | 40/13 | QC | QD |
| 1967 | Big Car 88 | 3.08:1 | 42/13 | QE | QF |
| 1967 | Big Car 88 | 3.23:1 | 41/12 | QG | QH |
| 1967 | Big Car 88 | 3.42:1 | 41/12 | QI | QJ |
| 1967 | Big Car 98 | 2.73:1 | 41/15 | QK | QL |
| 1967 | Big Car 98 | 3.08:1 | 40/13 | QM | QN |
| 1967 | Big Car 98 | 3.23:1 | 42/13 | QO | QP |
| 1967 | Big Car 98 | 3.42:1 | 41/12 | QR | |
| 1967 | Toronado | 3.23:1 | 41/12 | QO | - - |
