The carriers mounting bolts are differently off set. The Zilla axle is a larger diameter. using different bearings. The shocks are different. As much of a witch it is to mount the 91 92 250 swinger in the 250 and the Zilla swinger in a 500, I just can't imagine pissing around trying to interchange the 2. That being said, the Zilla swinger would allow the 250 to use the longer heavier axle on a shorter swinger.