Saw your email on this, sorry for not getting back to you sooner. We introduced the V-ROD baseplate in 10/11, so any binding models older than that will not have the ability to use the Yes, I Cant system. That older baseplate is what is now on the current Arsenal bindings.
Right now we don't offer the Yes, I Cant pads as a separate purchase; they're only available with the Targas and 390 Boss. However to answer your question, the pads will work on the regular 390, as both the 390 Boss and 390 use the V-ROD baseplate tech.
Definitely let us know if you've got any other questions and we'll get back to you asap.