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 Code Location
Engine Code letters on 6-cylinder engines are suffix of Engine Identification Number, which is stamped on a pad located at right hand side of engine block and to rear of distributor. On V8 engines, engine code letters are first two letters in production code number. On all 350" engines, number is located on left side of engine block below front two spark plugs. On 455" engines, number is located on left side of engine block below rear two spark plugs.
| Engine | Code Letters |
|---|---|
| 250" 6-Cyl. 1-Bbl. | CCA, CCB, CCC, CCD |
| 350" V8 2-Bbl. | XC |
| 350" V8 4-Bbl. | XB |
| 455" V8 4-Bbl. | XF |
| 455" V8 4-Bbl. (Stage 1) | XS |
| 455" V8 4-Bbl. (GS Rivera) | XA |
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.