The Electronic Trigger, part No. 6000-8931, was installed down by the cold air intake. Mysteriously, no screws were included with this item, but luckily we had two more lying around from the HI-6 kit. This baby box simply plugged between the HI-6 and the LT1 adapter harness, and its ground wire was routed to the nearest factory chassis ground screw on the radiator crossmember. At a suggested $189.86, an extra wallet whack for OBD-II guys--but almost certainly necessary.