4.3 Chevy Engine Block Identification

The 4.3-liter Chevy engine can be identified by the engine-code stamping numbers found on a machined pad located near the front of the passenger-side cylinder head and usually obscured by the alternator.

Background

The 4.3-liter Chevy engine displaces 265 cubic inches and was manufactured between 1954 and 1957. A second version, the L99, appeared from 1994 to 1996, according to Novak-Adapt.com.

Size

The 4.3 of the 1950s featured horsepower ranging from 162 to 240 with a 3.750-inch bore and 3-inch stroke.

Stamped Numbers

Number 3703524 identifies the 1955 4.3 engine with no oil filter, 3720991 for 1956 and 1957, 3731548 for 1957 models with no side motor mounts and 10168588 for the L99.

Further ID

The 4.3 engine identification code also will include an assembly plant code, build date and suffix code.

Decoding the Assembling Plant

The single first letter will identify the assembly plant where the engine was manufactured, such as "K" for St. Catherines, Ontario, or "V" for Flint, Michigan.

Breaking it Down

Engine identification code K0830C denotes the engine was built at St. Catherines on Aug. 30 with the "C" standing for the 1957 Corvette with a three-speed manual transmission.

References

• 4.3 Chevy engine block casting numbers
• Chevy engine stamp codes
• Chevy small-block engine data