How to Identify a 427 Chevy Engineby Jeffrey Caldwell
The Chevrolet big-block 427-cubic-inch engine was available on some Corvettes, Camaros and full-size Chevrolet Cars produced from 1966 to 1969, when the engine was replaced with the 454. The 427 engine is a variation of the Chevrolet Mark IV big-block engine family and can appear outwardly similar to other engines in the Mark IV family such as the 396 and 402. The surest way to identify a 427 engine is to decode the engine casting number located on the engine block.
Locate the engine casting number on the rear of the engine block on the bell housing flange.
If the number is 3909802, it is a 427 produced from 1966 to 1967.
If the number is 3917215, it is a 427 produced in 1968.
If the number is 3919842, it is a 427 produced from 1968 to 1969 with an aluminum engine block.
If the number is 3931063, it is a 427 produced in 1969.
- If you are having trouble locating the casting number, use an automotive solvent to clean the bell housing flange. Road grime may be covering the number.
- Aluminum-block 427 engines (known by Chevrolet enthusiasts as the ZL1) are rare. If you are thinking about buying what someone claims is a ZL1 or aluminum big-block Chevy engine, have an experienced Chevrolet restorer or mechanic examine the engine.
- Ultimate American V-8 Engine Data Book 1949-1974; Peter C. Sessler; 1999