not all parts are dependent on the CC or displacement b/w two cars. Yaris and echo are the same cars essentially so most parts should be swappable. you can easily swap alot of parts from...for e.g. a 1.3 sedan into a 1.0 four door hatchy.
it all depends upon what type of part you want to swap? wheels, brake system, suspension might be straightforward but ABS is technical as it involves sensors / ecu.
so what exactly u wanna swap?