NV Engines .061 helicopter head

This head arrived today. I got it to use on my Cox GTP Nissan for its enhanced cooling over the stock heatsink.

I have never owned a norvel engine, so didn't know if it would fit. Since many heads are sold saying they fit cox and norvel, I figured it would. I also didn't know if it used a button style glowplug, like the glowbee heads, or if it had a normal threaded glowplug. Now that I have it, its a globee style head button. I need to order some of those, I don't have any. I'm thinking the merlin ones will fit. Wonder what temp range would be best for a car, especially to help with a good reliable idle.

The one strange thing about the heli head, is there are no flats of any kind on it, no holes, or wrench fittings at all. I guess I just wrap it in a cloth and hand tighten it down. I hope that will be enough to hold when high revving on the car.

-edit- Added a picture of it next to my new silver TD 049.