Where Is the GM Engine Identification Stamp?

Where Is the GM Engine Identification Stamp?

General Motors displays its GM identification numbers on the head and bottom-end of its engines. Each casting number represents a different sized engine variant.

The following list shows casting numbers from seven General Motor engines.

  • 12556743 is used for the 1999 LS small block V8 engine
  • 12559895 is used for the 2000 LS small block V8 engine
  • 12562317 is used for the 2001 LS small block V8 engine
  • 12550592 is used for the LS1 engine
  • 10106179 is used for the LT small block V8 engine
  • 10205245 is used for the 1993 LT small block V8 engine
  • 10174390 is used for 1991 LT small block V8 engine