it is possible yes, biggest thing is the diffs. ex access cases are nice since it allows you to service diffs a lot easier. your best bet would be to buy two full diff in bulk heads, that way you can upgrade the plastic cup from the .21 to a aluminum cup. also the new bullet proof diff would be a nice way to go, if you get them from a chop shop, look for a set out of a flux or new XL. you also need new shock towers to go with them and the purple brace. the skid plates are also different so you will need those, and bumpers. the radio box can be upgraded as well to get rid of the pics, to the ez access set up. new tvps, to get the upgraded look of the x and new design, and transmission so you can pop the top off instead of splitting the case. basically your best bet is to buy a roller, and transfer your stuff from a .21 over, cheaper, and easier.