There's a little more work to put a Fox body into an A-body, most go with a explorer due to their 31 spline axles and the fact that they just about mount in with only some slight mods without having to cut down.
Mustang and Rangers only have the 28 spline and the rangers only have drums unless you can get a 2010 or newer model cheap. Also be aware that you either have to have a U-joint adapter or a driveline from a crown Vic to cut down (plus their aluminum). At the end of it all...it just comes down to choice and the amount of work you're willing to do.
