do they run the Ford type ends and traditional type circle track hubs?
Floater axles help with running rear disk setups. Supposed to help with rear pad knock back. Forgot the reason for this, but you can look it up.
Also if you run new axle tubes you can run inner axle seal to keep diff oil in the center housing and from leaking out ends on cornering. Fitting them in OE Chrysler tubes is tricky.