* 4.3L Vortec V6: This was a common engine choice.
* 5.7L Vortec V8: A more powerful option.
* 6.0L Vortec V8: The largest engine available.
Therefore, there's no single answer to the engine size. You need to check the specific vehicle's documentation (like the vehicle identification number (VIN) or the owner's manual) to determine which engine is installed.