Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Identification: Notes
Vehicle identification number stamped on plate attached to top of instrument panel on left side and visible from outside. Sixth digit indicates model year. For further information, see "Model Identification " below. Letter suffix of Engine Production Code Number indicates engine displacement and various equipment. Engine number is stamped on pad at right side of engine at rear of distributor.
| Engine & Model | Suffix Letters | |
|---|---|---|
| 153" | (Chevy II) | OA, OC, OH |
| 230" | (Chevy II) | BA, BB, BC, BD, BF, BH |
| (Chevelle) | BA, BB, BC, BD, BF, BH | |
| (Camaro) | BA, BD, BF | |
| 250" | (Chevy II) | CM, CN, CQ, CR |
| (Chevelle) | CM, CN, CQ, CR | |
| (Camaro) | CM, CN, CQ, CR | |
| (Chevrolet) | CA, CB, CC, CJ, CK, CL CQ, CR, CS, CT | |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.