You could Look into a bench harness too worst case, I know efi connection has a few for chevy engines.ZZP won’t ship my turbo kit and items on that order until I send them my ECM file for them to calibrate. Theoretically, I should be able to grab a piece of steel and bolt all of the grounds from the harness and engine to it, connect up the battery and have power to the OBD2 and ECM to pull the file, correct?