The 3.3 arms will work w/ either 3.3 stuff or 2.5 stuff. Only difference between the 3.3 and 2.5 arms is a little cut out for clearance on the wider diameter 3.3 sliders.
To do the 3.3 sliders and 3.3 knuckles need to be done together. You can't one without the other.
I can't decide if its more fun
to make it...
or break it...