If you’re trying to identify what a small block Chevy engine was originally built as, the Small Block Chevy suffix code is one of the most important pieces of information you can find.
While casting numbers tell you what block you have, suffix codes tell you how that engine left the factory—including the original vehicle application, transmission type, horsepower rating, and engine configuration.
This Small Block Chevy Suffix Code Lookup guide explains how suffix codes work, where to find them, how to decode them correctly, and why they matter when restoring or valuing a classic Chevy.
What Is a Small Block Chevy Suffix Code?
A Small Block Chevy suffix code is a short alphanumeric code stamped onto the engine’s identification pad during final assembly. It identifies the engine’s original factory configuration, not just the block itself.
Suffix codes can indicate:
- Original vehicle application (Camaro, Chevelle, Corvette, truck, etc.)
- Transmission type (manual vs automatic)
- Horsepower rating
- Engine option package or emissions configuration
Unlike casting numbers (which are cast into the block), suffix codes are stamped, making them more specific—but also easier to lose during engine machining.
Because suffix codes were reused across years and applications, reputable references such as Chevy engine code stampings charts are useful for cross-checking interpretations.
Suffix codes are a key part of originality verification, but they’re only one piece of the puzzle when determining if a classic Chevy is numbers matching.
Small Block Chevy Suffix Code Lookup Tool (1955–1979)
Use the Small Block Chevy suffix code lookup tool below to search factory engine suffix codes used from 1955–1979.
Enter the suffix code stamped on your engine’s ID pad (for example: DZ, CE, or CMJ) to see the original engine application, displacement, transmission type, and notes about verification.
Search Small Block Chevy Suffix Codes (1955–1979)
Type a Small Block Chevy suffix code (example DZ) or filter by CID, transmission, and year.
| Suffix | CID | Years | Trans | HP | Application | Notes |
|---|
Important: Small block Chevy suffix codes are often reused across different years and applications.
Always verify your results by cross-checking:
- The block casting number
- The casting date code
- The vehicle VIN (when applicable)
Where to Find the SBC Suffix Code
On most small block Chevy engines, the suffix code is located:
- On a machined flat ID pad
- Near the front of the engine block
- Typically, on the passenger-side deck surface, just ahead of the cylinder head
This area is often hidden by accessories, brackets, or grime, so cleaning is usually required before the code is readable.
Tip: If the ID pad looks unusually smooth or blank, the suffix code may have been removed during decking.
How Small Block Chevy Suffix Codes Are Structured
Most SBC engine stampings follow this general format:
F0114MB
| | |
| | └ Suffix code
| └ Assembly date (month/day)
└ Assembly plant prefix
The suffix code (usually the final 2–3 characters) is what you decode to determine the engine’s original application.
Because Chevrolet reused suffix codes across different years and displacements, suffix codes must always be interpreted alongside casting numbers and date codes.
👉 Before decoding a suffix code, confirm the block itself using the Chevy Small Block Casting Numbers Lookup.
Small Block Chevy Suffix Code Lookup (Common Examples)
Below are commonly encountered SBC suffix codes. This list is not exhaustive, but it reflects codes frequently seen in restorations, swaps, and project engines.
| Suffix Code | Typical Years | CID | Notes |
|---|---|---|---|
| CE | Various | 350 | Common service replacement suffix; multiple applications |
| CMJ | Various | 350 | Used across multiple passenger car applications |
| 3N | Late 1970s | 305 | Found in several GM vehicle lines |
| EA | Mid-1960s | 327 | Passenger car applications |
| EB | Mid-1960s | 327 | Higher-output variants |
| HR | 1960s | 327 | High-performance applications |
| TBS | 1960s | 327 | GM body-specific usage |
⚠️ Important: The same suffix code may appear in different years with different meanings. Always cross-reference with casting numbers and date codes.
Why Small Block Chevy Suffix Codes Matter
Suffix codes provide details that casting numbers cannot.
Together:
- Casting numbers identify the block family
- Suffix codes identify the factory configuration
This is critical when:
- Verifying a numbers-matching engine
- Restoring a car to period-correct specs
- Evaluating engine value during a purchase
- Avoiding incorrect parts or assumptions
For example, two engines with the same casting number may have very different suffix codes—one originally built for a truck, the other for a high-performance passenger car.
Common Mistakes When Decoding SBC Suffix Codes
Assuming the suffix code alone is definitive
Suffix codes are powerful, but never standalone proof.
Ignoring casting date codes
The date code must align logically with the suffix code year range.
Trusting generic charts without verification
Many charts oversimplify suffix codes and ignore overlap across years.
How to Properly Identify a Small Block Chevy Engine
Experienced Chevy builders follow this order:
- Identify the block casting number
- Decode the casting date code
- Read the suffix code
- Measure bore and stroke
- Confirm 2-bolt vs 4-bolt mains
Skipping steps leads to misidentification.
A thorough small block Chevy identification guide explains why suffix codes must be verified alongside casting numbers and date codes.
Frequently Asked Questions About Small Block Chevy Suffix Codes
What does a Small Block Chevy suffix code tell you?
It identifies the engine’s original factory application, including vehicle type, transmission, and horsepower rating.
Are suffix codes the same every year?
No. Chevrolet reused suffix codes across different years and engine combinations.
Can suffix codes confirm a numbers-matching engine?
They help—but true verification requires matching casting numbers, date codes, and VIN stampings where applicable.
What if my SBC has no suffix code?
Many engines were decked during rebuilds, which can remove the stamping. In that case, identification relies on casting numbers and physical measurements.
More Small Block Chevy Identification Tools
For complete verification, continue with:
- Chevy Small Block Casting Numbers Lookup
- Small Block Chevy Date Code Decoder
- Chevy Cylinder Head Casting Numbers Guide
- Classic Chevy Value Estimator
- How to Restore a Chevy Small Block V8
- Classic Chevy VIN Decoder
Small Block Chevy Suffix Code
A Small Block Chevy suffix code tells you what an engine was born as—but only when interpreted correctly.
Used alongside casting numbers and date codes, suffix codes are one of the most accurate tools available for identifying and verifying classic Chevy engines.
About the Author
Gary Thompson
Gary Thompson is a classic Chevrolet enthusiast and researcher behind OldChevys.com, where he focuses on accurate, practical guidance for identifying, restoring, and evaluating vintage Chevy vehicles.
Gary’s work centers on Small Block Chevy engine identification, including suffix codes, casting numbers, date codes, and VIN verification. His approach prioritizes verification over assumptions, reflecting how real-world restorers and buyers avoid costly mistakes when engines have been rebuilt, swapped, or misrepresented over time.
Content on OldChevys.com is written from hands-on research and long-standing reference material, not simplified charts or one-line answers.
Editorial Standards & Disclaimer
This Small Block Chevy suffix code lookup guide is provided for educational and informational purposes only.
Suffix codes are used to identify an engine’s original factory configuration, but they are not definitive on their own. Chevrolet reused many suffix codes across different years, engine sizes, and applications.
Before relying on a suffix code for restoration decisions, purchases, or numbers-matching claims, always verify:
- Block casting number
- Casting date code
- Engine suffix code
- Partial VIN stamp (when present)
- Physical characteristics such as bore, stroke, and main caps
OldChevys.com does not sell engines or parts and has no financial incentive tied to engine identification outcomes. The goal is clarity, accuracy, and helping enthusiasts make informed decisions.
How This Lookup Tool Is Maintained
The suffix code lookup tool on this page covers Small Block Chevy engines from 1955–1979 and is designed as a reference aid, not a guarantee of originality.
Data is periodically reviewed and updated as:
- Verified corrections are identified
- Clarifications are required due to suffix reuse
- Additional historical documentation becomes available
Last updated: 12/15/25
This page and its lookup tool are reviewed regularly to ensure accuracy and relevance.
Have a verified suffix code example or correction to share? Contact Gary and it will be reviewed against trusted sources.
