I don't really know the details of how these things work behind the scenes in the phone, but I'm 99% sure that would not work or end up well and no that would be porting. Porting would be taking the software from the Bionic and modifying it so it works with the DX, much more than plug-and-play, so to speak.
You'd brick your phone. The bionic is partitioned differently then the droid X and the fxz is going to allocate the partition tables based on the fixed space of 16gb that is in the Bionic versus the 8gb in the Dx
A forum community dedicated to Android phone owners and enthusiasts. Come join the discussion about applications, recovery, developments, styles, reviews, accessories, classifieds, and more for Unbuntu, Google Nexus, HTC, Motorola, Samsung or other Android models!