Just a quick post. The Dynamic EFI products use a stock GM ECM. However, there is better firmware, data logging, and analysis features. If you want or need OEM capability to pass smog, or just want a great upgrade to a factory ECM check out the EBL Flash and EBL Flash P4 systems.
No chip buring or swapping, flash in a new calibration (within seconds) via the same data cable as is used to log and view the engine data.