This LS1 EFI harness is designed specifically for the popular 1999-2002 Camaro/Firebird PCMs (service numbers 9354896 or 12200411. This plug and play harness is the easiest way to transplant an LS1 using the stock ECM. This harness is 4 feet longer than the standard length #60508 to allow more mountingh options for the ECM Emissions harness available #60325