On our 07 classic 2500hd it is a full float iirc. If you are looking at them you could pop off the hub cap cover and confirm. I would think it would be a full floater as most of the work vehicles I see are 2500s.
Yeah, easiest way to tell is pop a rear center cap and look for the ring bolts.
Most of those should be full float, but from what I gather there are a few semi floats out there that use the smaller 9.5" ring gear vs the 10.5" in the full float.