@Joeprunc is correct, to mount Radar Vectors on a HO you need the aluminum plate version. I am tweeking a set on a Coeff-X now and after an initial adjustment period and some advice from this site like them quite a bit. They are SO comfortable.
One additional bit of advice on the Radar plates, I had to file the slotted holes on the front plate a little for width and length to get them on my ski. Nothing too radical but something I would definately do prior to mounting everything up. That way when you are dialing things in on the water you can easily get the full range of adjustment if needed.