roundy round racers
In the past, I understood that a floater was short for a full-floating rear end. On this assembly, the rear wheels were supported by the housing independent of the axle shaft. This kept the wheels and brakes on the car when an axle shaft broke. Same thing is used on most 1 ton + trucks.
What I don't see in the photo that might be useful would be a bracket upon which a caliper may be mounted.