yeah i wanted to know too, heard that the center universals are not the same since the crt has a longer chassis. also the spur gears are different different. heard of bce x2 conversion?
Besides stiffer a-arms, what is the difference between the X1 and X2 CRT?
Also they were designed at different times, that is often a big difference. Plus you will not be able to find a 3yr old used crt x2... But you can definately get an x1 that way.