i had .010 clearance or more all around, rotated the engine to ensure even measurement.
i had the box mounted on rear the fender under the airbox towards the bottom, lots of air movement there with the intake always pulling across it i figured.
i got it since it wasnt much more pricewise than than the 2 wire kit, and at the time i was running all stock bulb setup, with EI, but now i have changed over to the led taillight, and H4 bulb headlight, ans LED wedge bulbs in the gauges, so i think the 2 wire will be more than enough now.
i had an old 2 wire i pulled off another bike for now and threw a single phase mighty max on it to keep on the road for now. its working great actually